下列哪个方法用来定义线程的具体行为，也就是定义线程体A． Java中的类可以有多个直

We always regard dogs as man’s best friends. But what about cats?

Cats can also do us a favor sometimes.

Here is a comparison of the two animals.

A Friend Helps You When You’re Sick.

Dogs	When Catherine lay down on the sofa, Pepe stared(盯) into her eyes and kept sniffing(嗅). After being pushed away, he suddenly jumped onto her chest. That’s when Catherine felt a pain that made her visit a doctor, and a fast-growing cancer was found. Months later, however, Pepe started staring and sniffing again. It seemed strange, but sure enough, Catherine’s cancer had spread.
Cats	Alana immediately finds a chair when Tee sits and stares directly into her face. That’s because Tee is warning her that she is about to faint(昏倒), which can happen as often as three times a day. But Alana won’t get hurt if she sits down. Not only does Tee warn Alana, but also her husband. Then the cat stays with Alana until she recovers.

A Friend Saves Your Life

Dogs	Ryan fell into the water by accident. The river was full of ice, and Ryan was very cold and his body temperature was dropping dangerously low. Luckily, he was found by Chelsea, who was playing with her dog, Zion. “Zion knew the boy was in trouble,” says Chelsea. “Ryan grabbed onto the dog’s collar, and Zion just turned around and came back to the bank.”
Cats	Bernice says: “I was sleeping in my bedroom, and then I was woken by Joey screaming and running”. Then she found smoke around her. With Joey helping her, she managed to get out of the door. “I found him in a mailbox when he was young and now I feel very lucky. Without him, I’d have probably died in the smoke.”

小题1:When Alana is about to faint, Tee will ________.

A．stare at her and keep sniffing

B．jump onto her chest suddenly

C．sit and stare directly into her face

D．scream and run小题2:What can we learn about Ryan?

A．He likes swimming in rivers.

B．He has a lovely dog, Zion.

C．Chelsea helped him swim back to the bank.

D．He was in danger when he was found by Chelsea.小题3:What happened when Bernice was sleeping?

A．She was badly hurt in a big fire.

B．She found the brave cat in a mailbox.

C．A fire broke out when she was sleeping.

D．She ran out of the burning house with the help of firemen.

小军是广州某重点学校学习，学习成绩优秀，深受老师喜爱，同学也很愿意和他交朋友。但是，自去年下班年开始，他偷偷到网吧上网、QQ、玩游戏，在网络的虚拟世界里流连忘返，学习成绩急剧下降，和老师、同学的交往日渐减少。老师和父母做了许多工作，但他仍然迷恋网吧，不能自拔。

（1）你认为小军发生这种变化的原因是：（2分）

①自身原因：                                                              

②社会原因：                                                              

                                                               

（2）小军想走出网络游戏泥潭，但不能自控，假如你是小军的好朋友，应该怎样帮助小军？（4分）

（3）在网络交往中，小军应该怎样对待网络？（4分）

下列选项中，关于电除尘器说法正确的是（）。

A．电除尘器系高压直流静电除尘设备，电晕线接高压直流电成为负极，阳极板接地成为正极

B．由于高压电场的作用，产生气体电离一电晕放电现象，使粉尘也有带有负电

C．大量带负电的粉尘粒子被吸尘极进行电中和而逐渐沉积下来

D．电除尘器主要由壳体、尘土散发装置、排灰收纳装置等组成

圆钢制品配件焊修时，两段对接中心偏差不应超过（）mm。

A.0.5

B.1

C.1.5

对于一个小国（价格接受国）来说，最优关税为（）。

A.零

B.禁止关税

C.毫无疑问的是正值

D.随着国家需求弹性的增加而增加