I _______ like science but I think it is very useful.

A． not

B．don’t

C．am not

D．no

心功能不全最早的体征是()

A．下肢水肿

B．胸腔积液和腹水

C．舒张期奔马律

D．肝颈静脉回流征阳性

E．阵发性夜间呼吸困难