题干

下列与声现象有关的说法中正确的是(  )

A:宇航员在太空中不能直接对话,因为真空不能传声

B:汽车安装的倒车雷达是利用超声波工作的

C:看电视时调节音量是为了改变声音的响度

D:高速公路两旁的隔音板可防止噪声的产生

上一题 下一题 0.0难度 选择题 更新时间:2017-02-05 06:04:38

答案(点此获取答案解析)

A,B,C

同类题3

根据短文内容,从短文后的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。

Fora lot of parents, sending their kids off to college is a bittersweetexperience. I think a lot of teenagers head to college without any idea abouthow money works. Don't let that happen to your college kid. Help themunderstand these issues before they step into that first class.

·Budget,budget, budget. ____ So start by making sure you understand budgeting and havebegun to use it as part of your financial plan.

·Independencemeans responsibility. Living away from home means you have to take care ofyourself. ____ Food doesn't just drop out of the sky, and gas doesn't magicallyappear in their car. Independence means responsibility.

·____Even if your kid is going to a small community college, they'll still probablyhave a few thousand dollars of tuition to pay. If you break it down, one classcan cost $1,000 at the very minimum! And that doesn't even include books.

·Choosea major wisely. ____ This isn't a must before they step on campus, but simplyplant a seed that gets them started thinking about what they want to do withtheir life. You don't want them graduating with a degree that leaves themunfulfilled or unable to find a job.

·Friendsmatter. ____ Who you hang out with definitely influences how you spend moneyand the decisions you make. Without being overbearing, remind them howimportant it is to have positive friends who build them up instead of bringingthem down.

Remember,as a parent, just be there for support and to streng then these principles throughouttheir college experience.

a.College isn't cheap.

b.Cherish your opportunity.

c.Help your teenager find his or herpassion.

d.However, not all friends can be reallydepended on.

e.New friends mean new opportunities andsocial situations.

f.Do your best to prepare your son ordaughter for what that means.

g.If you aren't using a budget, it'll bedifficult to convince your kid to use one.