问题补充：
to carry out the plan in time, they will make careful prepatations.
A. Determine
B. Having been determined
C. Determined
D. being determined
答案：
A. Determine
B. Having been determined
(答案→)C. Determined
D. being determined
解析： be determined to do下定决心做某事；下定决心这个动作表示已完成。因为后面用的将来时will make，所以用determined.
