Mrs. Green always helps her mother even though going to work _________most of her day.

A．takes out

B．takes down

C．takes up

D．takes off

法洛四联症缺氧发作的主要原因

A．心力衰竭

B．脑血栓

C．脑水肿

D．继发肺部感染

E．右心室流出道漏斗部肌肉痉挛