have trouble doing sth.我只知道介词后动词得加ING。变动名词。

have
trouble
(in)
doing
sth
为一固定搭配，但现在常把in省略。类似的还有：
have
a
good
time
(in)
doing
sth
have
fun
(in)
doing
sth
have
some
difficulty(
in)
doing
sth
等