过敏性紫癜主要表现为（）
A.皮肤紫癜
B.关节肿痛
C.腹痛
D.便血
E.血尿
参考答案：A, B, C, D, E
---A stranger gave me an umbrella when I was caught in the rain.
---________.
A．First impression is half the battle
B．A friend without faults will never be found
C．There is kindness to be found everywhere
D．Two heads are better than one
( )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
