试题

According to Paragraph 1, the practice of tipping in the U.S.            .

A : was regarded as a sign of generosity

B : was considered essential for waiters

C : was a way of rewarding diligence

D : was optional in most businesses

【28考研辅导课程推荐】：28考研集训课程,VIP领学计划,28考研VIP全科定制套餐（公共课VIP＋专业课1对1） , 这些课程中都会配有内部讲义以及辅导书和资料，同时会有教研教辅双师模式对大家进行教学以及督学，并配有24小时答疑和模拟测试等，可直接咨询在线客服老师领取大额优惠券。