问题 选择题

下列说法中,正确的是(   )

A.每种金属都有确定的电阻率,电阻率不随温度变化

B.导线越细越长,其电阻率也越大

C.一般金属的电阻率,都随温度升高而增大

D.测电阻率时,为了提高精度,通过导线的电流要足够大,而且要等到稳定一段时间后才可读数

答案

答案:C

选C.金属的电阻率,随着温度的变化而改变,温度升高,电阻率增大.A错,C对.电阻率的大小与导线的粗细和长短无关,B错.由于电阻率的大小与温度有关.测电阻率时,不应使通过导线的电流过大,或通电时间过长,因为这会使导线温度明显升高,从而导致测量不准确,故D错.

多项选择题
阅读理解

阅读理解。
阅读下列应用文及相关信息,并按照要求匹配信息。

首先,请阅读以下手机游戏介绍:
AAngry Poo Game
Are you looking for a free game with amazing graphics, 100's of
levels, and completely original? Well then, Angry Poo may not be
for you! This is a free game that might make you laugh for a few
minutes. Laugh your head off at the hilarious sound effects.
BBingo
The classic bingo game with balls drawn from a
basket, a lightboard showing the balls drawn to date and three cards on which
you mark your squares as the numbers are drawn. It may not be the
prettiest bingo game you can play, but it is the most functional!
CCountry Guess
A simple game where you are given hints about a country's name
and you have to guess what the country is. Test you geography
skills. It's a wonderful game that helps your learning of geography
and entertains you at the same time while you're playing.
DCrazy Taxi
You're a crazy cabbie racing against the clock! Swerve to avoid
other cars…or just jump right over them! You must get to the
checkpoint no matter what! It's designed for the lovers of cars, and
it also helps you develop driving skills too!
EAttack of the Flying Goats
In this Adventure Game your mountain town is being attacked by a
seemingly endless number of Flying Goats sticking their tongues
out and wagging them at everyone! You've been recruited to take
on the adventure of holding these creatures back at all costs.
FDeveloper Rescue
The year is 2020. Apple Inc has finally decided to kidnapping the
lead jailbreak developers they have hated for so many years. Upon
learning of Apple's plans you decide to rescue the developers
before Apple can succeed in kidnapping them.
请阅读以下人员信息,然后匹配人员与相关游戏:
     1. Frank wishes to get a game for his new Apple phone. He loves to play those kinds of games
in which his role is a pilot, a brave soldiers or a tough man of other kinds who fight to rescue people
in trouble.
     2. Charlie wants to download a game with different levels of difficulty for his mobile phone. He
wants it for free and hopes that it will bring him lots of laughter. Of course, he wishes it would have
wonderful visual and sound effect.
     3. Eddie is a young man with sporting blood. He likes to do things that can bring him challenges
and adventures. So when it comes to mobile phones games, he definitely wants to get one adventure
games for his phone.
     4. For Brad Green, no games can attract him more than those related to cars. Now he would
love to download a car racing games for his new phone. And of course, he wishes to get one that
can help to improve his driving skills at the same time.
     5. Tony loves to play games with his new cell phone. It seems that nothing can prevent him from
playing those games, his father Mr. Greg has got a new idea instead. He wants to find a game that
could help with Tony's knowledge of geography.