制作木楔如何选材？
参考答案：
制作木楔，应选用干燥的红松木，通常情况下多选用废弃的旧门框。
— _____________ books are they?
— They are Panda's. He likes reading books. [ ]
A. What
B. Whose
C. Where
最可能的诊断是
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．肺动脉狭窄
