----,the door of the lab could not be opened.

题目

----,the door of the lab could not be opened.
a.For the key was missing
b.Having lost the key
c.He lost the key
d.The key gone
选：d
为什么不能选a?for表示“因为”引导从句不可以吗?
With many items she needed( )for her 50-birthday-party,Mrs Brown went to the supermarket with a big basket.
a.to be bought
b.to buy
为什么不能选b?主语不就是Mrs Brown吗?又不要别人去买?

答案

for表因为不能放在句首
item 和buy之间有逻辑上的被动关系.