The trip was hard at first. But it was smooth .A. at the endB. in the endC. of the endD. b

问题补充：

The trip was hard at first. But it was smooth .

A. at the end

B. in the end

C. of the end

D. by the end

答案：

A. at the end

(答案→)B. in the end

C. of the end

D. by the end

解析：短语辨析。A. 最终；在终点 B. 终于；最后 C. 结束 D. 到……为止。句意：路程开始很艰难，但是最后顺利了。选项A强调在一个点，故选B。