本集核心英语单词及例句：

1.gun (n.)枪
I've shot hundreds of quail with that gun.
我用那只枪打死过几百只鹌鹑。
 

2.trade (n.)贸易；买卖
The two countries do little trade with one another.
两国之间很少有贸易往来。
 

3.rifle (n.)步枪；来福枪
The soldiers kept a tight hold of their rifles.
战士们紧握他们手中的枪。
 

4.cannon (n.)大炮；机关炮
We heard the bang of a cannon.
我们听到轰的一声炮响。
 

5.upgrade (vt.)提升；使升级
We need to upgrade the status of our teachers.
我们需要提升老师的地位。

6.protect (vt.)保护
Laws are made to protect citizens' rights.
法律是为了保护公民的权利。

7.major (adj.)主要的
He said the issue was not a major irritant.
他说那个问题不是什么大问题。