20周末胎儿发育特征为()
A.吸吮反射良好
B.四肢活动活泼
C.指甲已超过指端
D.临床上用普通听诊器可听到胎心
E.身长25cm,皮下脂肪发育良好
参考答案:D
The number of teachers in our school _______ greatly increased last term.A number of teachers in this school ______from the countryside.
A.was;is
B.was;are
C.were;are
D.were;is
IPv6提供了3种寻址方式,它们是 【6】 、任意通信与组播通信。