We are bound with difficulties in carrying out this research.
A. to meet
B. to have met
C. meeting
D. having met
网友回答
(答案→)A. to meet
B. to have met
C. meeting
D. having met
解析：考察固定搭配。固定搭配be bound to do sth一定要做某事；句意：在执行这些研究的时候，我们一定会遇见很多的困难。B项中使用了不定式的完成式，表示该动作发生在谓语动词之前。这与句意不相符。故A正确。