Question

20．People around the country were excited __________ the astronauts came back to the earth safely．（　　）

• A． unless
• B． but
• C． until
• D． because

Answer 1

分析 句意：全国各地的人们都很激动，因为宇航员安全地返回地球．

解答 答案：D．根据People around the country were excited （全国各地的人们都很激动）和the astronauts came back to the earth safely（宇航员安全地返回地球）可知前后是因果关系，四个选项的含义分别是A．unless除非； B．but但是；C．until直到；D．because因为．故D正确

点评 考查从属连词．
1．because 是连词，其后接句子，例 如：
He is called Mitch，because his name is Mitchell．
2．because of 是复合介词，其后接名词、代词、动名词、what 从句等．例如：
We could see him wasting away because of his illness．