题目内容
He had already walked three or four miles ________ he saw a cart, half-full of grass, by the side of the road.
[ ]
A.when
B.while
C.until
D.unless
答案:A
练习册系列答案
相关题目
题目内容
He had already walked three or four miles ________ he saw a cart, half-full of grass, by the side of the road.
A.when
B.while
C.until
D.unless