题干

如图所示,有一段12 cm长的汞柱,在均匀玻璃管中封住一定质量的气体,若开口向上将玻璃管放置在倾角为30°的光滑斜面上,在下滑过程中被封住气体的压强为(大气压强p0=76 cmHg)(  )

A:76 cmHg

B:82 cmHg

C:88 cmHg

D:70 cmHg

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答案(点此获取答案解析)

A

同类题5

从下面方框中选出10个单词,并将其正确形式填写在答题卡相应题号后,使短文意思正确通顺(每词限用一次)。

come    different    excite     go good    live      

loud     low      mean     nature time    west

    An old saying goes, “When in Rome(罗马),do as the Romans do.” I learned the ____ of this when I studied in Russia.

    One day I invited some of my Chinese friends to a famous local restaurant in Moscow. My guests and I were ____  from visiting Red Square and happy about our meeting. We had a warm  chat  until  the  waiter  told  me  that  we  were  being  too  loud.  We  turned  our  voices ____ .But this didn't last long. The waiter came over to us two more ____  with the same message.

    How bad an impression(印象) we must have left on the local people! In China, it's ____  and important for a host to make a ____  atmosphere(气氛).However, in Russia and ____  countries, having a meal in a public place means you must keep your voice low. You need to be polite to others.

    I felt bad about this. Even though we tried our ____ , it's very difficult to develop a new habit.

    Russians have their own special habits. My Russia friend, Andrey always looks around and thinks for a while before leaving home. I asked him why he did this. “Aha,” Andrey said, “in Russia, people always take about a minute ____  over things and plans in their minds before leaving. So they won't leave anything necessary behind.”

    Finding the ____  between cultures is much fun. I'd like to keep my eyes and mind open.