Living in the central Australian desert has its problems, _____getting water is not the least.

A．as

B．of which

C．whose

D．for what

下列何种先心病可出现周围血管征

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