骨瘤好发于（）
A．短骨
B．长骨骨骺
C．长骨干骺端
D．扁骨
参考答案：D
Look ! _________ students are doing morning exercises on the playground .
A．hundreds of
B．hundred of
C．hundred
D．hundreds
理想的冠桩直径应为根径的
A．1/5B．1/4C．2/3D．1/2E．1/3
