题干

如图所示,相同的瓶子里装入了不同质量的水,用木棒敲击瓶子时,可发出不同音调的声音,其中音调高的是____ 瓶;若用嘴贴着瓶口向瓶内吹气,也会发出声音,此时的发声体是____ 。

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答案(点此获取答案解析)

甲,瓶内空气柱

同类题2

阅读下面短文,从短文后各题所给的A、B、C和D四个选项中,选出可以填入空白处的最佳选项。

    A student at Hellesdon High School in England has been called “Rubbish Girl” by bullies (欺凌者) for her environmentally-friendly ways.1, that has not stopped her from cleaning up the environment.

    Using the basket on her bicycle, 12-year-old Nadia has been 2 rubbish along her two-mile route to and 3 school since September of last year.4her good intentions, some of the kids at Nadia's school have nicknamed(给……起绰号) her “Rubbish Girl” and have bullied her for her selfless efforts to help the 5. But instead of letting them bring her down, she's using their 6as motivation(动力).

    “I'm not going to 7 doing the right thing because of them,” she said. “I'm doing something to 8 the world which they also live in. It's everyone's job. We are all 9for keeping this world safe, instead of 10 it's always someone else's job.”

    Nadia's mom, Paula, said she is11 proud of Nadia for not only standing up to her bullies, but also standing up for what she believes in. “I told her she had two 12 — she could either stop collecting rubbish, stop attracting their 13 so that they would leave her alone, or she could face the challenge, be the “rubbish girl” and keep her 14

    As a result of the local 15 attention, Nadia has created a Facebook group named “Team Rubbish Girl”,16she shares updates on her green efforts. Positive 17 have poured in, all in 18 of Nadia, encouraging her to carry on with the green effort.

    “Sweetheart, you are a star that 19 really bright above the rest. Hold your head high and never let others 20 you. You are doing something selfless and amazing. Shame on the bullies.” wrote one of the local citizens on her Facebook page.

同类题3

阅读《五猖会》片段,回答问题。

    ①因为东关离城远,大清早大家就起来。昨夜预定好的三道明瓦窗的大船,已经泊在河埠头,船椅,饭菜,茶炊,点心盒子,都在陆续搬下去了。我笑着跳着,催他们要搬得快。忽然,工人的脸色很谨肃了,我知道有些蹊跷,四面一看,父亲就站在我背后。

    ②“去拿你的书来。”他慢慢地说。

    ③这所谓“书”,是指我开蒙时候所读的《鉴略》,因为我再没有第二本了。我们那里上学的岁数是多拣单数的,所以这使我记住我其时是七岁。

    ④我忐忑着,拿了书来了。他使我同坐在堂中央的桌子前,教我一句一句地读下去。我担着心,一句一句地读下去。

    ⑤两句一行,大约读了二三十行罢,他说:

    ⑥“给我读熟。背不出,就不准去看赛会。”

    ⑦他说完,便站起来,走进房里去了。

    ⑧我似乎从头上浇了一盆冷水。但是,有什么法子呢?自然是读着,读着,强记着,——而且要背出来。

粤自盘古,生于太荒,首出御世,肇开混茫。

    ⑨就是这样的书,我现在只记得前四句,别的都忘却了,那时所强记的二三十行,自然也一齐忘却在里面了。记得那时听人说,读《鉴略》比读《千字文》,《百家姓》有用得多,因为可以知道从古到今的大概。知道从古到今的大概,那当然是很好的,然而我一字也不懂。“粤自盘古”就是“粤自盘古”,读下去,记住它,“粤自盘古”呵!“生于太荒”呵!……

    ⑩应用的物件已经搬完,家中由忙乱转成静肃了。朝阳照着西墙,天气很晴朗。母亲,工人,长妈妈即阿长,都无法营救,只默默地静候着我读熟,而且背出来。在百静中,我似乎头里要伸出许多铁钳,将什么“生于太荒”之流夹住;也听到自己急急诵读的声音发着抖,仿佛深秋的蟋蟀,在夜中鸣叫似的。

    ⑪他们都等候着;太阳也升得更高了。