55＿＿

44.Why are rainforests important to the world?

• A、They can provide food for different kinds of insects.
• B、They can lower the temperature around the Equator.
• C、They are home to various kinds of plants and animals.
• D、They produce the best wood for house building.

17.The teacher asked all the students in the class to keep their eyes＿for a minute.

• A、close
• B、closed
• C、to close
• D、closing