Question

I don't think you will have any difficulty( )his English speech

A to understand B understand C in understanding 为什么选C

Answer 1

have some difficulty （in） doing sth.为固定搭配。
虽然 think 引导的宾语从句否定前置、提前至主句，
但句中some 在否定句仍需改为any, 固定结构就变成：
have any difficulty （in） doing sth. 固定结构的其后仍需跟V+ING，
因此，选C

Answer 2

have difficulty (in) doing sth. 在做某事方面有困难，in可以省略
因此选C

Answer 3

have difficulty (in) doing sth. 在做某事方面有困难，in可以省略
固定搭配

Answer 4

have difficulty in doing sth
固定搭配，做……有困难

Answer 5

have difficulty in doing sth