若a+b=0，则a与b互为（ ）。

根据短文内容，从短文后的七个选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

—— Sara, I’ve been looking forward to our yearly camp out for 3 weeks.       小题1:     . Camping under the stars. This is the life.

—— Yeah. But Paul,      小题2:      . The weatherman said it was going to rain later tonight.

—— Nothing can prevent our adventure. Those weather reports are never right.

——     小题3:      .

—— Ah. Don’t worry. 

—— Paul, Paul. Did you remember to bring our raincoats just in case, like I told you?

—— Uh…no. I left them at home.

——      小题4:    . 

—— How about playing a card game? 

—— Uhh. I left them next to the picnic table. Hey, you want to me to go out in this rain and get them?

—— No. That’s Ok.     小题5:     . 

—— Well, we could go down the mountain and stay at that hotel we passed on the way up.

A．And it said there was a chance of heavy winds.

B．I’m a little worried about the weather though.

C．How much do you suggest we take with us?

D．It’s up to you.E. What are we going to do now? 

F. It’s going to be a wonderful day for hiking tomorrow.

G. So what now? 

已知一台水泵运行时的轴功率为40KW，运转电流为90A，电压380V，cosΦ=0.58，电动机直接传动，求该泵的效率是多少？

“中华人民共和国突发事件应对法”自（）日起施行。

A.2006年11月1日

B.2007年11月1日

C.2008年11月1日

炎热季节搅拌混凝土时，宜采取措施来控制水泥的入搅拌机温度应不大于（）

A.20℃

B.40℃

C.60℃

D.80℃

小车“三条腿”运行的原因及消除方法有哪些？