问题
选择题
In American, a friend inviting you to a restaurant doesn't mean that he or she will pay for the meal ______ you are told ahead.
A．until
B．unless
C．although
D．if
答案
答案：B
题目分析：句意：在美国，如果你没有被提前告知的话，一个朋友邀请你去餐馆意思并不是她（他）要买单。A. until 直到B. unless如果不C. although虽然D. if如果。根据句意，故选B。