______的基本原理是将要传送的明文通过Hash函数转换成报文摘要，报文摘要加密后

影响寿夭的因素有哪些？

下列实例属于超重现象的是[ ]

A．汽车驶过拱形桥顶端

B．荡秋千的小孩通过最低点

C．跳水运动员被跳板弹起，离开跳板向上运动

D．火箭点火后加速升空

机泵运行一段时间后，应进行“一保”，主要工作内容包括不见得吃些、清晰、检查、调整、紧固。

下面与pH较低的注射液配伍时易产生沉淀的药物是（）

A.水不溶性的酸性药物制成的盐

B.水不溶性的碱性药物制成的盐

C.水溶性的酸性药物制成的盐

D.水溶性的碱性药物制成的盐

E.水不溶性无机盐，

The use of computer graphics (1) many diverse fields. Applications (2) from the production of charts and graphs, to the generation of realistic images for television and motion pictures to the (3) design of mechanical parts.To encompass all these uses, we can adopt a simple definition:Computer graphics is concerned with all (4) of using a computer to generate images.We can classify applications of computer graphics into four main areas:Display of information, Design, (5) ,User interfaces.

A．scope

B．bound

C．range

D．area