Empty talk is harmful to the nation, while practical work can help _________ thrive．

A．that

B．this

C．it

D．which

某病人贫血，出血及发热，经化验确诊急性白血病，病人发热的原因是

A．血小板少
B．骨髓被破坏
C．出血被吸收
D．红细胞破坏多
E．细菌感染