问题
选择题
The little girl crossed a large area of grassland into the woods _________ she realized that she was lost.
A．when
B．as
C．after
D．before
答案
答案：D
考察before特殊用法。Before在…之前；…以后；结合句意可知D正确；句意：那个小女孩走过一大片草地进入森林以后才发现自己迷路了。
