Because he is head of the government he is supposed .A. /; to takingB. /; to take the lea

问题补充：

Because he is head of the government, he is supposed .

A. /; to taking

B. /; to take the lead

C. the; taking the

D. the; taking

答案：

A. /; to taking

(答案→)B. /; to take the lead

C. the; taking the

D. the; taking

解析：考查冠词和固定搭配。职务、头衔前面不能加冠词，head在此意为“首长，首脑”，前面不适用冠词，排除C、D；be supposed to do sth应该做某事，排除A。故选B。