1. biomass
   diesel
2. alkaline batteries
   steam

Diesel is a kind of fuel that doesn't require a spark to create an explosion, and thus the power stroke, in an engine. It is also common in large trucks.

1. demolition
   farming
2. grading
   transportation

"Semi" is short for "semi-trailer." It combines a tractor and a trailer to transport a number of goods efficiently.

1. construction
   farming
2. excavation
   possibly any of these

"Tractor" is a broader term than many people think. It's any vehicle with heavy, strong-gripping wheels, which pulls equipment behind it. It's most often mentioned in terms of agriculture, but is used in other settings.

1. fluid-dynamic
   hydraulic
2. hydroboosted
   steam-powered

Hydraulics don't just come into play in human-powered machines. The human body uses it, too -- if you have high or low blood pressure, that's a hydraulic issue that needs adjusting.

1. compressive
   aural
2. pneumatic
   oxygenated

"Pneuma" is the Greek word for breath. So "pneumatic" is the word for a machine which, while powered by something else, uses pressurized air or other gases to move arms or other parts. It's a cousin to the word "hydraulic."

1. an archaeological excavation
   a parking-garage construction site
2. a shipyard
   a wheat field

Container cranes move freight modules, known as containers, on and off ships. But the usefulness of containers is that they can be loaded onto trains and trucks directly, without being opened and the cargo redistributed.

1. true
2. false

Cranes got their names from their long necks. Fun fact: The movie "Bulletproof Monk" exploits this dual meaning in a prophecy about the novice monk fighting "while cranes circle overhead."

1. continuous-track locomotion
   a hemi-engine
2. an earth-moving blade
   a rear claw

"Locomotion" here is a fancy word for "way of moving." Both tanks and bulldozers have tracks, made of many narrow interlocked plates, that continuously rotate and allow the machine to roll forward.

1. caterpillar track
   durable track
2. millipede track
   hardtack

A soldier observing a tank apparently gave this replacement for the wheel its name. A continuous track is long and low to the ground, hence the resemblance to the insect.

1. a lower stance/height
   less maintenance
2. even weight distribution
   they look cool

Tracks distribute a bulldozer's (or other machine's) weight over a greater area. This reduces the chances of getting stuck in loose or wet ground. Heavy machinery, after all, often operates on unpaved surfaces.

1. combine harvester
   knuckle-boom truck
2. pile driver
   front-end loader

The "pile-driver" (it's usually written as one word in wrestling) is a move in which a wrestler picks up his opponent, turns him upside down, and drops to a seated position, appearing to slam him ( or sometimes her) into the mat. Side note: we feel like it's a missed opportunity that there's not a "knuckle-boom" move in wrestling, too.

1. establishes posts and supports
   powers the blades of a combine
2. evens out cement or stone
   lifts smaller but heavy machines

In lighter projects, the equivalent is a post-holer, which is used is the building of fences. For major construction, though, a pile driver is used.

1. equalizer
   grader
2. slater
   smoother

You'll often see graders used in road work. They have a large blade in front, and look a lot like snowplows.

1. articulated
   reticulated
2. jackknifed
   flexible

Although we use the word "articulate" to describe someone good with words, in engineering it means "jointed, for better turning capability." In the UK you'll often hear the word "articulated lorry" for a semi-trailer with a middle joint.

1. dolly
   flat
2. leaf
   back-loader

This is a pretty flexible term. It's also applied to a "hand truck," the upright wheeled cart warehouse workers move boxes with, and a piece of equipment in film-making.

1. a crane
   an excavator
2. a skip loader
   a tractor

Excavation is the removal of unwanted earth or other material from a site. The excavator is sometimes simply called a "digger."

1. They are smaller.
   They are larger.
2. They don't use hydraulics.
   They can be run automatically.

Excavators are usually hydraulic in their workings (though sometimes pneumatic). A power shovel uses interior cables and winches to operate its arm, to which the bucket is attached.

1. true
2. false

Though the backhoe is generally in that rear position, it's not named for that. The name comes from the way the arm and bucket scoop in a backward motion, compared to the forward position of an old-fashioned shovel to the human digging with it.

1. a back-loader
   a backhoe loader
2. a pivoter
   this combination of machines does not exist

"Backloader" would have saved a syllable! But someone went for clarity over time-saving here.

1. cherry picker
   elevator
2. hydraulic lift
   heightener

Utilities workers often use these to access the tops of power poles. They are put into use by rescue workers, too, in emergency situations.

1. electric shock from contact with wires
   electrocution by lightning strike
2. injury from falls from the bucket
   illness from smoke inhalation

Utilities workers who use these machines are often in close proximity to wires. Care must be taken by the operator to avoid them while still getting access to the parts of a utility pole that need work.

1. a landfill
   a scrapyard
2. a warehouse
   any of these

Compactors use large blades to compact (as the name says) material into a more manageable size. Landfills use them to make more space available; in scrapyards, they are used as car crushers, and warehouses use them on waste material.

1. the Bronze Age
   ancient Greece
2. the Middle Ages
   the Renaissance

The ancient Greeks were no slouches at inventing things. They used cranes powered by beasts of burden to construct some of their taller buildings.

1. water, of course
   coal
2. hydrogen
   horses or donkeys

It requires a lot of heat to create steam from water. That's where the burning of coal comes in. Nowadays, the power shovel uses electricity as its power source (which itself is generated from fossil fuels burned elsewhere).

1. bird
   insect
2. locomotion system
   both #2 and #3

The biggest equipment maker in the world is Caterpillar. It is named for the caterpillar track feet of many of its machines, which in turn was named for the insect that crawls low on the ground.

1. Grinds down stone
   Deepens open-pit mines
2. Shreds agricultural waste
   Removes material from a body of water

Dredging either removes material (often soil) from the bed of a body of water, or moves it to the side to increase depth. For example, dredging might be done to create a channel deep enough for large ships to come into a harbor.

1. advanced
   topper
2. suction
   Venturi

As you'd expect, it's simply called a suction dredger. A long tube sucks material off the floor of the sea, lake or river.

1. hoe
   loader
2. crane
   yarder

"Loader" is a fairly broad designation in heavy machinery -- hence the number of possible prefixes. A loader is a simply a machine that picks things up to move them elsewhere, whether it is something disposable, or something of value.

1. wheels
   tracks
2. it can have either

It's more common for a loader to have heavy, big wheels, like a tractor. But a few have bulldozer-style tracks.

1. a boring machine
   a forklift
2. a paver
   a pile driver

A forklift is a small truck used for moving cargo over short distances. They are often found in warehouses, and are not as versatile as the varied types of loaders.

1. combine
   dredger
2. paver
   none of these

This is a bit of a trick question. A knuckleboom is an adjective, describing a type of arm on a loader or a crane. A "knuckleboom crane" has an arm that folds at a "knuckle," allowing greater range of motion.

1. Pfizer
   Le Corbusier
2. Kubota
   Zondervan

Kubota is a Japanese maker of tractors and other heavy equipment. Though not always a big name in America, the company dates back to 1890 in Japan.

1. crampon
   carabiner
2. snowcat
   chairlift

Snowcats are often used for grooming snow at ski and snowboard resorts. Fun fact: A snowcat was Scatman Crothers's co-star in a climactic scene in "The Shining," when he rides one to the rescue of Wendy and Danny Torrance.

1. true
2. false

One significant battle that required armored bulldozers was Normandy in WWII. They were used to clear the French beaches of obstructions, allowing Allied soldiers to advance and claim territory.

1. cargo containers
   bales of hay or grass
2. soil
   workers in a mine

"Mantrip" is the common name for the underground personnel carrier used by miners. Sometimes they run on rails, like the old-fashioned train cars they replaced. Others have wheels, like trucks.