defensive
a.防御性的
We need both defensive and offensive weapons to face attacks from neighboring countries.
我们需要防御性及攻击性的武器以对抗邻国的攻击。
defensible
a.可防御的
A castle built on a high mountain is easily defensible.
兴建在高山上的城堡容易防御。
operation
n.操作；营运；手术
Are you familiar with the operation of this machine?
你熟悉这台机器的操作吗？
Three doctors were performing an operation on the patient.
三位医生正为病人动手术。
operator
n.操作人员；接线生，总机
All the machine operators in our factory are well trained.
我们工厂所有的机器操作人员都经过良好的训练。
Operator, please connect me to Mr. Wilson.
总机，麻烦你把我接给魏尔逊先生。
operational
a.操作上的
Should you have any operational problems, just let me know.
你若有任何操作上的问题，请径自告诉我就可以了。
assume
vt.假定，认为（以that从句作宾语）；负起（责任）
Paul assumed that his girlfriend was joking when she said he was ugly.
保罗的女友说他很丑时，他认定她一定是在开玩笑。
After his parents passed away, the boy assumed the burden of raising the family.
男孩的父母亡故后，他便负起养家的责任。
associate
vt.使有关联 vi.交往
Lung cancer is mostly associated with smoking.
肺癌大多与吸烟有关。
If I were you, I wouldn't associate with that guy. He's a gangster.
如果我是你的话，我不会和那名男子有所往来。他是帮派分子。
associate
n.合伙人 a.副的
Jason is one of my business associates.
杰森是我的事业伙伴之一。
Maggie is the associate editor of that magazine.
玛琪是那家杂志的副编辑。
association
n.协会；联合
We decided to set up an association of photography lovers.
我们决定成立一个摄影爱好者协会。
The exhibition was sponsored by the government in association with local businesses.
这场展览是由政府联合当地企业赞助举办的。
equip
vt.配备（常用被动语态）
All the classrooms are equipped with state-of-the-art facilities.
所有的教室都配有最先进的设备。
equipment
n.装备（集合名词，不可数）
This camera is the most important piece of equipment I have.
这台相机是目前我拥有最重要的一项配备。