1.Ihavesomedifficultwhathesaid,becausehecouldn'texpresshimselfclearly.A.tounderstandB.understandingC.toknowD.know但不明白为什么选B啊,选A不行吗?为什么要加ing而不用to打错了，应该是difficulty

Question

1.I have some difficult _______ what he said,because he couldn't express himself clearly.
A.to understand B.understanding C.to know D.know
但不明白为什么选B啊,选A不行吗?为什么要加ing而不用to
打错了，应该是difficulty

Answer 1

B
have difficult (in) doing sth
in 常省略.表示“在做.上有困难”