若函数y=sin（ωx+φ）（ω＞0）的部分图象如图，则ω=____．

阅读下面短文, 从短文后各题所给的四个选项(A、B、C、D)中, 选出可以填入空白处的最佳选项。
    One day,it was raining heavily and I didn't have an umbrella,I had just1a bus and had to walk back to my house.I2walking in that direction,when I heard somebody shouting,“Sister,”“Sister.” I looked back and3the stationery（文具）shopkeeper.I went to him and asked what was the4.He said that since it was raining heavily,I could take a5in his shop,have a look at his new6and go home when the rain stopped.For a moment I hesitated（犹豫）,but the7of getting to have a look at the pens made me nod.
    To my surprise,I found that the8was larger than I thought.The stationery shopkeeper offered me a chair and took out the pens for me.I9a beautiful parker（派克）pen and had a try.It10so smoothly that I wanted to buy it with all my heart,11as expected,it was very expensive.The shopkeeper said,“I can give you the pen for ninety-five dollars12one hundred.”I looked up and thanked him for the13,but refused politely as it was14quite expensive for me.By that time,the rain had15,and after appreciating his16,I quickly walked back to my house.
    After that day,the shop became my17place to hang out .The shopkeeper used to18me pens always at discount prices and very often also offered me tea.He had much information about all kinds of pens and other writing instruments.19both of us knew nothing about each other,we had a deep friendship based on our common 20.

阿伏加德罗常数值是N_A，标准状况下，若某氧气和氮气的混合气体mg含有b个分子，则
ng该混合气体在标准状况下的体积是

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我爱小草

    很多人爱花，因为花朵娇艳；不少人爱杨柳，因为杨柳柔美。然而，我却喜爱春天里那绿油油的小草。

    小草是报春的使者：它最早把春天到来的讯息报告给人们，不信你看我家门前的草坪就是这样，它们是那样富有生机。每年冰雪融化，大地还未脱尽冬装，你如果用手拨开紧贴地面的枯草，就会看见一棵棵小草已经钻出像针一样的嫩绿的尖儿——它悄悄随着春天的脚步来到人间。

    一阵春风吹来，小草左右摇摆，有时甚至紧贴地面，小草坪就像我家门前铺着的一块地毯。①别看小草那么柔弱，可它永不向暴风雨低头。一天，一阵狂风过后，突如其来下了一场暴雨。风雨过后，我赶紧看那小草。呀！小草被折磨得奄奄一息了。有的歪歪斜斜，有的倒在泥水里。但是小草慢慢地又挺直了腰，尽管脸上还带着晶莹的泪珠。②它们仿佛在骄傲地说：“狂风吹不倒我们，暴雨砸不垮我们，泥水淹不死我们。”③是啊，“野火烧不尽，春风吹又生，”白居易这诗句写得多好！是啊，严冬一过，小草又生机勃勃地生长起来了。