— Must I finish my homework now?

— No, you _____. [ ]

A. must not

B. don't

C. needn't

D. can't

心导管检查血氧含量右心房高于上、下腔静脉的先心病是( )

A．房间隔缺损
B．室间隔缺损
C．动脉导管未闭
D．肺动脉狭窄
E．法洛四联症