我国的小学最早出现于______。
A．唐朝 B．殷周时期C．宋朝 D．清朝
参考答案：B
解析： 殷周时期，我国就已经出现了小学。
He made another wonderful discovery, ________ of great importance to science. [ ]
A. which I think is
B. which I think it is
C. which I think it
D. I think it is
治疗效果差（）
A.硬膜外血肿
B.硬膜外脓肿
C.空气栓塞
D.全脊髓麻醉
E.刺破胸膜
