下列哪个部位骨折容易并发骨坏死（）
A.股骨颈
B.桡骨远端
C.手舟状骨
D.距骨
E.髌骨
参考答案：B, C, D
---It is so crowded. Where is Jack?
---He is very tall. We can easily _____ him in the crowd.
A．discover
B．find
C．spot
D．locate
有性繁殖获得的苗称为“（）”。
