Question

【题目】I have a tight budget for the trip, so I'm not going to flythe airlines lower ticket prices.
A.once
B.if
C.after
D.unless

Answer 1

【答案】D
【解析】句意：我旅行的预算很吃紧，所以不打算坐飞机，除非航空公司降低票价。unless相当于if...not，，根据句意，选D。