有耳毒性（） A．地西泮 B．胍乙啶 C．普萘洛尔 D．庆大霉素 E．格列奇特

一小球从屋檐自由下落，通过一扇高2m的窗户用时0.2s，问小球从距离窗户上缘多高处下落（g取10m/s²）？

大量输血后病人可出现（）

A.高钾血症

B.碱中毒

C.凝血异常

D.低体温

E.酸中毒

Her sister ______ a rich man. They ______ for twenty years.

A．married with; have married

B．married to; have married

C．married; have been married

D．has married with; have been married

以下哪项属于“五小类”商户（）

A、超市

B、点心店

C、小快餐

D、小便利店

简述旅游资源的特征。