题干

以下说法中正确的是(  )

A:单晶体的所有物理性质都具有各向异性

B:悬浮在液体中的花粉颗粒的无规则运动是热运动

C:相同温度下,氢分子的平均动能一定等于于氧分子的平均动能

D:随着分子间距离增大,分子间作用力减小,分子势能也减小

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答案(点此获取答案解析)

C

同类题4

根据短文内容填空。

    In the coming summer holidays, you will probably visit the Shanghai Expo. Before you head off the Expro, please read the following tips so that you behave properly and show off China's best face to visitors from other countries.

When waiting in a line

    Wait patiently instead of cutting to the front of the line. If you have to leave your spot in line and want to come back, tell the people standing in front of and behind you. Ask them to kindly hold you spot, and thank them when you return.

When touring the Expro

    Don't touch or climb on exhibits. Visitors are allowed to take pictures and videos around the Expro, but when cameras are not welcome, don't turn yours on. If souvenirs are handed out, don't push and scream. Be polite and wait your turn.

When attending shows

    If you are late, wait until the break to enter. It will disturb other audience if you walk in late.

    It's very important to leave in the middle of a musical or stage play. If an early exit is necessary, you can leave after a scene is over.

Keep quiet during a performance. Before the performance starts, either turn off your mobile phone or set it silent mode. Never answer your phone while a performance is going on.

    After an excellent performance, clap your hands warmly. Don't laugh at the performers when they make mistakes.

When having meals

    Don't talk loudly at meals. With many hungry visitors waiting, don't stay too long at your table after you have finished. Politely move on to another place.

Title: Showing off China’s best face

Occasions(场合)

Don'ts

Dos

Waiting in a line

●Don't ____ to the front of the line.

●Wait patiently.

●Thank those for holding your spot after you are ____.

Touring the Expro

●Don't touch or climb on exhibits.

●Don't use your cameras when they are ____.

●Don't push and scream for ____ souvenirs.

●Be polite and wait for your turn.

____ shows

●Don't walk in late.

●Don't leave in the middle of a musical or stage play.

●Never answer your phone ____ a performance.

●Don't laugh at the performers’ ____.

●Enter during the ____, if you are late.

●Wait until a scene is over, if you make an early exit.

●Turn off your mobile phone or set it to silent mode.

●Clap your hands ____.

Having meals

●Don't talk loudly at meals.

●Don't stay too long at your table after meals.

●Politely move on to another place.

Purpose: To remind people to behave properly before ____ visitors at the Expro.