improve his oral English he took part in the summer course A. So as toB. In order toC. So

问题补充：

improve his oral English, he took part in the summer course

A. So as to

B. In order to

C. So that

D. In order that

答案：

A. So as to

(答案→)B. In order to

C. So that

D. In order that

解析：短语用法辨析。A项不能放在句首。CD项后面要接句子，只有B项后面接动词或者动词短语表示目的，句意：为了提高他的口语，他参加了夏令营。故B正确。