Question

Some plants can take in carbon dioxide we breathe out and give ______ oxygen to us.

A．in case

B．in turn

C．in return

D．in addition

Answer 1

C

介词短语辨析。A以防；B依次，轮流；反过来；C作为回报；D另外；结合句意可知C正确。句意：一些植物能够吸收我们呼出的二氧化碳，作为回报并给我们氧气。