1. The Arctic Circle ________ through northern North America, Europe, and Asia.

2. Earth’s gravity pulls everything g towards ____ the Earth.

3. The forces _________ earthquake are the same ones that build mountains.

4. Since the eighteenth century __________ the major genre of literature in most literate societies.

5. Under a microscope, _________________ of a computer chip looks like a network of aluminium tracks.

6. Dinosaurs became extinct 64 million years _________ first people ever appeared on Earth.

7. Venus is almost the same size as the Earth, ___________mountain ranges are much higher.

8. In concrete poetry the primary consideration is the way that ______ in the poem.

Scientists are now only beginning to understand the factors______ cigarette addiction

Agricultural ___ largely responsible for the unfolding of vitamins and minerals early in the last century.

Each summer the Roanoke Historical Association sponsors a play that shows___ about the fate of the early colony

Agriculture requires a steady supply of water to keep the plants alive, so___ in areas with a lot of rainfall

Even though___ about $4,000 to fully train a hearing dog, these dogs are generally given without charge to qualified candidates.

The reactor core of a nuclear reactor is housed in a steel vessel___ by a thick layer of concrete.

The properties of every protein depend on how___ are arranged in the molecular chain.