单选题
The group led by experienced guide Jake Watts ______ most of Toronto's top sites by the time the tour ends. A. would see B. was being seen C. has seen D. will have seen
【正确答案】
D
【答案解析】解题的关键是从句意来判断应当填入将来完成时态的动词。将来完成时态表示到将来某个时间点为止，某种行动将要完成。与将来完成时态相匹配的时间短语是by the time，请熟记。