试题详情

When the glaciers（ ）after the last ice age,the five Great Lakes of North America were formed.

n the new snowfall. Thats equivalent to the current mass loss from the whole of the Greenland ice s

The first blacks were brought to North America as _____.

pe in the middle of the lake,with one end of the pipe near the bottom and the other end in the air.

n the destruction of all rainforests and the melting of allArctic ice. What is NOT the result of c