Question

A teacher’s too long speech can make the students’ patience _________．

1. A.
   to run out of
2. B.
   to run out
3. C.
   run out
4. D.
   run out of

Answer 1

C
“老师讲的太多，会使学生失去耐心。”run out用尽，没有了，其主语是事物，此处用省略to的不定式作宾语补足语；run out of的主语是人，宾语是事物。