Based on fossil evidence, about how long ago did the first single-celled life form appear on Earth? 130 million years ago
1.5 billion years ago
2.5 billion years ago
4.1 billion years ago

Volcanic irruption is most likely to be violent when a) volcanoes near to the sea b) the neck of the volcano is sealed by a plug c) the lava is viscous d) the lava reaches the surface through a fissure e) the volcano is on the ocean floor

Write a 150-word essay describing the effect of people's activities on the environment in the region.

Which describes italy’s mediterranean climate? a. moist in the summer and dry in the winter b. mild and wet all year round c. cool in the summer and warm in the winter d. hot in the summer and mild in the winter