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已知tanα=﹣2，则sinαcosα﹣cos²α的值是（   ）

下列数量的各物质所含原子个数由大到小顺序排列的是(　　)

①0.5 mol氨气　②4 g氦气　③4℃时9 mL水④0.2 mol磷酸钠

乙肝疫苗的有效成分是乙肝病毒的一种抗原．接种该疫苗后，人体会产生相应抗体．该抗体（    ）

O 10,000 people come here every day.

欣赏下面一首现代诗，回答小题。

瀑布

洪 源

                                                                                                   要下山！要出谷！

                                                                                                   一声呐喊，

                                                                                                   从云崖上扑下，

                                                                                                   哪怕它粉身碎骨！

                                                                                                   向往的是——浩浩江河、茫茫大海，

                                                                                                   想念的是——展翼的风帆、击浪的桡橹，

                                                                                                   啊，全凭一腔燃烧的信念，

                                                                                                   脚下，才开辟出一条奔腾的生命之路。

(节选自《中国当代名诗一百首》)

将红墨水滴入水中，一会儿整杯水变红，这一现象中(   )

通读全文，根据短文理解，选择最佳答案填空。   

    Man began to make use of fire long long ago. Fire is useful in many ways, but sometimes it is dangerous. If you are not 1with it, it can burn things or even hurt you. A big fire can 2 forests and tall buildings. Sometimes a piece of thin paper can cause (引起)a big fire. So please remember not to smoke in the dry places like woods and forests. When you use candles at home, you should 3 your long hair away from the fire.

    But if there is a fire in our building, 4 should we do? Pour some water 5 your clothes. What's more, put a 6 towel (毛巾) over your mouth and your nose to keep the 7 out. You'd better run away from the fire as 8 as you can. But you mustn't rush! Or you may fall over and hurt yourself or others. Of course you should also call 9. On the phone you should clearly tell the firemen where the fire is to help them get there without difficulty. By the way, Do not 10 out of the window. Jumping may be more dangerous than the fire.

    Keep ourselves away from fire and safety is above all!

下列有关遗传说法正确的是（　　）

如图，在正方形ABCD的外侧，作等边三角形ADE，AC，BE相交于点F，则∠BFC为°.

下列各组数中数值不相等的是（  ）

下列运算正确的是（   ）

在弹簧测力计下挂一圆柱体，从盛水的烧杯上方某一高度缓慢下降，圆柱体浸没后继续下降，直到圆柱体底面与烧杯底部接触为止，如图所示是圆柱体下降过程中弹簧测力计读数F随圆柱体下降高度h变化的图像。根据图像回答下列问题：

朝鲜族主要分布的省区是(   )

如图，菱形ABCD中，若BD＝8，AC＝6，则该菱形的面积为.

天津《益世报》曾刊文称：“四五年来农民知识渐有进步。例如匪祸前，农民不知国家为何物，更不知世界上尚有其他国家，今则知之；昔之认为须有皇帝以统治天下，至今则认为人民也可以管理国家；昔不知开会为何事，今则不但知之，且可选举委员，当主席。此外农民所知新名词亦不少。”使农民发生巨大变化的主要原因是（    ）

选出你所听到的单词或短语。

Due the bad weather, the sports meeting had been put off.

下图是1907年发表的漫画（注；图中所示器具从右到左依次是坛，提匀、漏斗、壶)。其政治寓意是(   )

My mother  ，but my brother starts 

作为世界上最大的发展中国家,我国为推动构建人类命运共同体、促进世界共同发展作出积极努力。下列事件体现这一做法的是（  ）