胚胎造血首先在
A．肝脏
B．骨髓
C．胸腺
D．卵黄囊
E．淋巴结
参考答案：D
当我们的合法权益受到侵害时，正确的做法是 [ ]
A、及时寻求法律帮助
B、及时找人揍他一顿
C、采取一切手段进行报复
D、逆来顺受、忍气吞声
Haven't I repeated that you________have a holiday on Saturday if you work hard?[ ]
A. should
B. shall
C. must
D. have to
