剂量过大，可引起反射亢进、肌肉抽搐乃至惊厥的是（）
A.咖啡因
B.士的宁
C.尼可刹米
D.戊四氮
E.地西洋
参考答案：A
—Is this your eraser?
—No, it isn't. I think _____.[ ]
A. it her eraser
B. its her eraser
C. it's her eraser
D. it's him eraser
往复式压缩机排气终了时的压力（绝压）为2.4MPa，吸气终了时的压力（绝压）为1.2MPa，则压缩机的压缩比为20
