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问题 单项选择题

某人3点出门赶火车，若每分钟走60米，则比火车到站要晚5分钟抵达车站；若每分钟走75米，则比火车到站要早到4分钟。若火车在车站停靠10分钟，他至少要走多快才能不误车（检票时间忽略不计）（）

A．50米，分钟

B．52米/分钟

C．54米/分钟

D．58米/分钟

答案

参考答案：C

解析：

设到车站距离为x，则，解得x=2700。分，因此火车在3点加分到达。此人在路上最多走50分钟，速度最慢为2700÷50=54米/分钟。

选择题

某原子的摩尔质量是Mg?mol—1，则一个该原子的真实质量约为

A．M g

B．1/M g

C．M/6.02×1023g

D．6.02×1023/M g
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完形填空

阅读下面短文，掌握其大意，然后从下列各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。

Strange things happen to time when you travel. __11___the earth is divided into24 time zones, one hour apart, you can have days with __12___ or fewer than 24 hours, and weeks with more or fewer than seven days.

If you __13___ a five-day trip across the Atlantic Ocean, your __14___ enters a different time zone every __15___. As you enter each zone, the time __16___ one hour. Traveling west, you set your clock back; traveling east, you set it __17___. Each day of your trip has __18___ 25 or 23 hours.

­If you travel by ship across the Pacific, you ___19___ the internationaldate line. By agreement, this is the point __20___ a new day begins. __21___ you cross the line, you change your __22___ one full day, backward __23____ forward. Traveling east, today __24___ yesterday; traveling west, __25___ is tomorrow!

小题1:

A．Because

B．If

C．Although

D．When小题2:

A．much

B．more

C．many

D．less小题3:

A．do

B．make

C．go

D．travel小题4:

A．plane

B．train

C．car

D．ship小题5:

A．day

B．night

C．hour

D．time小题6:

A．goes

B．changes

C．shows

D．adds小题7:

A．ahead

B．upward

C．backward

D．fast小题8:

A．neither

B．either

C．both

D．nor小题9:

A．travel

B．trip

C．cover

D．cross小题10:

A．which

B．what

C．that

D．where小题11:

A．When

B．Where

C．While

D．Before小题12:

A．time

B．calendar

C．date

D．hour小题13:

A．and

B．or

C．but

D．still小题14:

A．changes

B．makes

C．becomes

D．goes小题15:

A．which

B．this

C．that

D．it
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