问题
选择题
Luckily ______ to be no one under the tree when it broke down.
A．it happened
B．there happened
C．there used
D．it had
答案
答案：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。