________of the chemical factories in their city _________pouring waste water into the river. It’s too dangerous.

The boy is_______tall_______he can join the school basketball team.[ ]

he explained , we understood .

Look at the bird over there! It’s so beautiful!— Wow! It’s a rare crane. It appears in this area.

How do you learn English so well?—______ chatting with my uncle in America-online. [ ]