轴承的基本代号由类型代号、宽（高）度系列代号、直径代号和轴承内径代号构成。

选出正确的单词填在横线上。

1. Jim is going to visit us ______________. (yesterday, today, tomorrow)

2. I worked hard at school ______________. (yesterday, today, tomorrow)

3. I clean my bedroom ______________. (yesterday, today, tomorrow)

4. He goes to school by car ______________. (yesterday, today, tomorrow)

5. Jenny ate an orange ______________. (yesterday, today, tomorrow)

6. We are going to go to Beijing ______________. (yesterday, today, tomorrow)

向监考老师申领一张长方形纸条，经过适当折叠后粘贴，制作一个正三棱锥，写上你的姓名后放桌面左上角，等老师前来收．

血管扩张药不包括（）。

A.硝普钠

B.利多卡因

C.硝酸甘油

D.酚妥拉明

E.尼卡地平

扩血管药物治疗心功能不全的主要作用机理是______

A．增强心肌收缩力
B．降低心肌耗氧量
C．降低心脏前、后负荷
D．减慢心率

图示为刀开关、熔断器与电源的四种连接方法，其中正确的接法是（）

A.图a

B.图b

C.图c

D.图d