TOEFL Longman Intro Structure Skills 5-6

A spacecraft is freed from friction ____ launched into space.

• it

• it is

• after is

• after it is

____ with their surroundings, or they hide in crevices for protection.

• Lobsters

• Lobsters blend

• Lobsters blending

• Because lobsters blend

_____ a ball-and-socket joint, the elbow is a simple hinge joint.

• While the shoulder

• While the shoulder is

• The shoulder is

• The shoulder

A car has several sections with moving parts, _____ of those parts is essential.

• good lubrication

• well lubricated

• and good lubrication

• and well lubricated

5. Bears cannot see well _____ small eyes.

• bears have

• because having

• because they have

• because of bears

_____ at the Isthmus of Panama, so animals were able to migrate between North and South America.

• A land bridge existed

• When a land bridge existed

• A land bridge

• With a land bridge

_______ mostly made of granite, it also contains some human-made materials.

• The Empire State Building

• The Empire State Building is

• Although the Empire State Building is

• Although the Empire State Building is built

Pressure differences make the eardrum vibrate _____ the ear.

• enters the sound waves

• as sound waves

• sound waves enter

• as sound waves enter

An optical microscope magnifies as much as 2,000 times, but an electron microscope ____ as much as a million times.

• magnifying

• it magnifies

• can magnify

• magnify it

If scientific estimates are accurate, ____ with the Earth about 20,000 years ago.

• the Canon Diablo meteorite collided

• the collision of the Canon Diablo meteorite

• the Canon Diablo meteorite colliding

• colliding the Canon Diablo meteorite