1.Saccharin(糖精), a sweetening agent that is hundreds of times sweeter than ordinary cane sugar, is a popular sugar substitute.
(A) enhancer (B)replacement (C)catalyst
2.When light enters a camera, it strikes the film, whose surface reacts to the light.
(A) filters through (B)makes contact with (C)damages
3.Permeable rocks have pores of sufficient size to permit water to pass through them.
(A) fluctuating (B)enlarged (C)adequate
4.Some theorists suggest that modern society produces more stress than did earlier periods of human life.
(A) tension (B)accents (C)trends
5.Our teacher stimulated us to study hard.
(A) simulated (B)faked (C)encouraged
6.United States Navy Admiral Alfred Mahan wrote many books on naval strategy and sea power.
(A)tactics (B)history (C)battles
7.Many of Edith Wharton’s best stories were completed under great personal strain.
(A) poverty (B)privacy (C)tension
8.Children who are provided with positive feedback for aggressiveness will incorporate this kind of conduct into their stock of behaviors.
(A)reserve (B)understanding (C)bond
答案：BBCAC ACA
详解：
1、replacement
n. 更换;复位;代替者;补充兵员
Replacement of sugar in your diet can be
difficult.
在你的饮食中更换糖肯定是困难的。
2、makes contact with
接触;与…联系
As a client-server protocol, the client
makes contact with the server.
作为一个客户端-服务器协议，客户端与服务
器进行联系。
3、adequate
adj. 充足的;适当的;胜任的
I have no adequate preparation.
我没有充分的准备。
4、tension
n. 张力，拉力;紧张，不安;电压
vt. 使紧张;使拉紧
The tension eased off slowly.
紧张局势逐渐缓和了。
5、encouraged
v. 鼓励( encourage的过去式和过去分词 );
支持;促进;鼓动
Children should be encouraged to be
independent thinkers.
应鼓励孩子们成为独立思考者。
6、tactics
n. 策略;战术;用兵学
Tactics differs from strategy.
战术有别于战略。
7、tension
n. 张力，拉力;紧张，不安;电压
vt. 使紧张;使拉紧
The tension eased off slowly.
紧张局势逐渐缓和了。
8、reserve
n. 储备，储存;自然保护区;预备队;缄默
;[金融] 储备金
vt. 储备;保留;预约
vi. 预订
I reserve the right to make my own
decisions.
我保留自行做出决定的权利。
From:https://www.zgghmh.com/CET-4/20003979.asp