He had no choice but to go on because it is their agreement that no one quit the plan ha

问题补充：

He had no choice but to go on because it is their agreement that no one quit the plan half way.

A. need

B. will

C. shall

D. can

答案：

A. need

B. will

(答案→)C. shall

D. can

解析：句意：他没有选择只有继续因为不能有人半途而费这是他们的协议。need需要；will表示意愿；shall允诺，命令。can有时，会。这里it是形式主语，that引导的是真正的主语。