题干

The voyages of travellers before the 17th century show that they were not ________ the sea even though they didn’t have modern navigational aids.
A.at the expense ofB.at the risk ofC.in the way ofD.at the mercy of
上一题 下一题 0.4难度 单项选择 更新时间:2011-07-15 02:36:42

答案(点此获取答案解析)