人类最早的造血地点是（）
A.卵黄囊
B.肝
C.骨髓
D.脾
E.胸腺
参考答案：A
5．I wonder if John has forgotten my number. I _____him to call me for the past two hours.
A．was expecting
B．have expected
C．have been expecting
D．expected
残疾人社区康复的基本原则是什么？
