Question

Luckily ______ to be no one under the tree when it broke down

1. A.
   it happened
2. B.
   there happened
3. C.
   there used
4. D.
   it had

Answer 1

B
本题考查there be句型与happen to的连用，根据句意可知需要用there be结构，happen to表示“碰巧”。句意：幸运的，当树倒下的时候，下面碰巧没有人。