-Life itself tells us it is necessary to learn to be     .One can hardly survive without help from other people in the world.

A．sensitive

B．competitive

C．grateful

D．careful

对心室颤动患者，每延迟电击除颤1分钟，死亡率可增加（）

A.3%～5%

B.6%～8%

C.7%～10%

D.10%～14%

E.15%～20%