按照保险范围不同，医疗保险分为普通医疗保险、住院保险、手术保险和综合医疗保险（）
参考答案：对
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 of
B．at the risk of
C．in the way of
D．at the mercy of
某病人，右T以下皮肤痛温觉缺失，深感觉保留，病损在：（）
A.左T后根
B.右T后根
C.右薄束楔束
D.右脊髓丘脑侧束
E.左脊髓丘脑侧束
