Question

【题目】A tourist will easily lose his way in shanghai ________ he has a map or a guide.
A.if
B.since
C.while
D.unless

Answer 1

【答案】D
【解析】句意：在上海旅游会很容易迷路除非他有地图或者指南。if 如果； since 从；while当……的时候； unless除非。根据前后分句句意可知该选D。