We have only one Earth. It’s our common _.A. familyB. houseC. homeD. room

问题补充：

We have only one Earth. It’s our common _.

A. family

B. house

C. home

D. room

答案：

A. family

B. house

(答案→)C. home

D. room

解析：四个选项分别表示家庭、房子、家和房间，根据题意选C，我们只有一个地球。它是我们共同的家园。