题干

在盛放浓硫酸的试剂瓶的标签上应印有下列警示标志中的(     )

A:

B:

C:

D:

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A

同类题3

完形填空

    There was my mother, standing in a fuzzy (毛绒绒的) pink bunny(兔子)costume. This can't be, 1 I thought to myself. Being ten was 2 enough.

    Our class was taking a trip to a convalescent home(疗养院) that day.I had 3 to stay at home pretending I'd caught some rare disease. My mother who's a(n) 4, sent me to school anyway.

    When we got there, I 5 wished for that 6. I'd fall to the ground and be 7the humiliation (耻笑) of anyone ever knowing that I 8every day after school there, dressed as a bunny.

    “Hi, Shelly!” The residents waved at me, “ Do you know them?” someone asked. “No! They 9 me for someone else. I'm Machille,” I responded. I didn't look up 10 I might make eye contact with them. Then, Mrs. Deist, our teacher, handed us tulips (郁金香) to give to the residents. I quickly went to the back of the 11. My mother just went along her way--- hopping(单足跳跃). Last year, we hopped together. 12, “I'm too old for that now”, I thought.

    I hid behind my class. “ Shelly, how about a game of Fish?” Lou asked. My class and teacher 13 and stared. “ Machille, do you know these people?” Mrs.Deist asked me.

“Um….yes!”  

    “Well you should 14 the way,” she said, smiling. So I stepped forward, handed a tulip to Rose, waved to Frank and gave Mr. Blusso a high-five.

    “My mother is in a convalescent home. I wish she could have someone like you to 15 her.” Mrs Deist said. My mother hopped over then. “This is my mom. Every day she looks after these special people who need nurses' care.” I stood straight as I 16 the information. My mother then explained a program where kids can 17 after school. The residents cheered at the18, and my class seemed excited, too.

    I realized how 19 it made me to make other people smile and feel good. I should never be 20 of that.

同类题5

阅读下面的文章,完成问题。

凶手WiFi

引用自《黑龙江省龙东地区中考语文卷》

    ①近日,一群来自丹麦的女学生用水芹种子进行实验,得出了惊人的发现:WiFi信号可能会损害健康。

    ②由于学校没有监测大脑活动的设备,女孩们选择了水芹种子作为研究对象。她们将12个装有水芹种子的盘子平分为两组,其中一组放在没有任何WiFi信号的房间里;另一组则放在两台运行中的无线路由器旁边。十二天的时间里,覆盖有WiFi的房间内,大多数种子变成了褐色,然后死亡。而另一间房里的种子则正常生长。

    ③虽然有人认为,种子之所以在覆盖有WiFi的房间中死掉,可能是路由器散热所致。但此项实验结果还是加剧了人们对WiFi辐射的恐惧感,有些家长和教师们要求校园内禁止安置无线路由器。

    ④与此同时,实验也得到了荷兰研究者的力挺。三年前,荷兰的科学家选用白蜡树作为研究对象,他们将这些树木分别放在距六个辐射源0.5米处的位置,辐射源的频段介于2412赫兹到2472赫兹,功率为100毫瓦——和无线路由器相似。靠近辐射源种植的树木,树叶上出现了“具有类似铅光泽”的物质,导致叶片的上下表皮死亡,最终掉落。

    ⑤但是,美国的一些研究者对这些研究成果表示怀疑,他们认为,由于WiFi采用的是低强度的无线电波传输信号,其威力只是微波的十万分之一。在一间覆盖WiFi的屋子里待上一年,受到的辐射量仅相当于用手机进行20分钟通话。

    ⑥不过需要提醒的是,如果WiFi使用不正确,也极可能对人体造成伤害。那么,作为普通用户,在使用无线路由器时应该注意什么呢?21教育名师原创作品

    ⑦首先,人体接受的辐射量跟频率有关,频率越高,伤害越大。因此,家中没有必要使用功率过大的无线路由器。

    ⑧其次,辐射危害大小还跟距离有关,距离越远,危害越小。如果家中有孕妇、小孩、老人或免疫力低下者,最好让无线路由器与他们的活动范围保持较远的距离。

    ⑨第三,最好不要将WiFi设备放置在卧室内,尤其是放在床边。如果不使用WiFi,最好将无线路由器关闭,以降低不必要的风险。

    ⑩还有,别在腿上使用笔记本电脑,最好将电脑放在桌子或托架上。