Atnight,plants

問題詳情：

 At night, plants _________carbon dioxide and at the same time _________oxygen. So, we may put some in our bedrooms to purify the air.

  A. take in, give out               B. take up, give off

  C. take in, give in                D. take off, give up

【回答】

A

知識點：動詞

題型：選擇題