X线心腰部凹陷见于
A．房间隔缺损B．室间隔缺损C．动脉导管未闭D．法洛四联症E．肺动脉高压
参考答案：D
The students _____ are hard-working and ready to help others should be praised.
A．who
B．whom
C．which
D．whose
A．大地
B．飞机
C．白云
D．运动员背着的伞包
