They ______ live in Shanghai.[ ]
A. doesn't
B. did
C. don't
D. do
答案:C
咳嗽性头痛
( )允许一方因为对方的行为或疏忽构成的违约而选择中止协议。
A.有效合同 B.可撤销合同 C.无效合同 D.不可撤销合同