已知方程组 ， 则其增广矩阵为 ．

在标准状况下，将aLNH₃完全溶于水得到V mL氨水，溶液的密度为ρg/cm³ ， 溶质的质量分数为ω，溶质的物质的量浓度为cmol/L．下列叙述中正确的是（　　）

同温同压下，瓦斯中氧气和甲烷的体积比是2：1时极易发生爆炸，此时氧气与甲烷的质量比是（   ）

阅读理解

    Can children improve their reading skills by reading to dogs? Researchers at the University of California, Davis, reported that the answer is yes. Just ask Taivion Scott. He began learning to read last year at Stanton Elementary School in Washington, D. C. He struggles with new words, but says it helps when a dog is sitting next to him.

    Izzy has been coming to school for a year with Denise Velasquez, a volunteer with PAL. PAL is People Animals Love, a private group in Washington, D. C. that brings dogs into schools and libraries.

    Denise Velasquez helped Taivion with his reading. She said, "I pulled Izzy in a little bit, too, so he could feel a little bit closer to her, and then we started to take it one word at a time because a whole book can be overwhelming, but a single word is something you can deal with. "

    Eric Reithel from the PAL programme says he can understand the children because he had problems with reading when he was young. He said, "They feel more confident when reading to a dog; a dog won't tell them that's the wrong word. "

    The Anacostia neighbourhood is the poorest area in Washington, D. C. , and it has the highest crime(犯罪) rate in Washington, D. C. Seventy-five percent of the students here are raised by a single parent, usually a mother. Reading to dogs helps the children with their reading. For example, Melvin Hansberry, one of the children here, says the dogs help him learn big words. He said, "It's like you're reading to your little sister or your brother. "

    Demaris Hamilton, a teacher's assistant, grew up in Anacostia and says the environment in many homes can make it hard for children to learn but when they come here, they get much love and attention.

下列句子中加点词语的解释，正确的一项是（  ）

补写出下列句子中的空缺部分。

补写出下列句子中的空缺部分。

定义运算= ， 称= 为将点（x，y）映到点（x′，y′）的一次变换．若=把直线y=x上的各点映到这点本身，而把直线y=3x上的各点映到这点关于原点对称的点．则p，q的值分别是（　　）

文学类文本阅读

阅读下面的文字，完成各题。

母亲的心愿

北方

“麻警官，您母亲又闹着要出小区，倒是没在小区里翻垃圾箱检垃圾，这都第四次了，我们劝不住，疫情的严重性您是知道的，怎么说她就是不听。知道您忙，可我们实在没办法，只能找您了。”

“我早晨过去又说了说，怎么还闹呢？吃喝都给她准备得很充足，口罩也买了，”麻利锋刚上卡点，母亲居住的社区张主任就打来电话。昨天张主任就为麻利锋母亲要出去给他打了半个小时的电话，最后还是麻利锋亲自回去，才把母亲担住了。

母亲越来越不听劝了。麻利锋最初担心母亲患上了阿尔茨海默症(即老年病呆症)，带她到市医院彻底检查，结果显示所有数据正常。大夫说人上了岁数，性格发生变化也不奇怪。

父亲在世时，母亲买菜做饭收拾屋子，还要伺候腿脚不便的父亲。每天不得闲，几乎不用麻利锋操心，自从父亲去世后，母亲似乎就变了，主要表现是话少了，还总爱在小区的垃圾箱里翻检废品。纸箱、矿泉水瓶、废报纸、泡沫板……只要是废品回收站要的，母亲一样也不会漏掉，起初，听小区门房的梁姨说过几次，好似母亲抢了人家的生意，话说得客气但不好听，麻利锋似信非信，家里见不到任何废品的影子呢，他忙得顾不上，就让老婆去盯了两次，果然看到身形瘦小的母亲踮着脚半截身子插在垃圾箱里，像个土拨鼠似地往外检废品。

母亲被抓了现行后，更加无所顾忌了，梁姨被进出的车辆登记收费拖住了手脚，只能眼睁睁地看着目标落入母亲的手中，碍于麻利锋的面子，再生气也不好明目张胆地夺回自己的地盘。

母亲是市五小退休教师，每月工资五千多。

麻利锋问地，缺钱吗？

不缺。

为啥检垃圾？那不是垃圾，是能回收利用的废品，找点事干。

麻利锋劝说多次无效，也不能整天看着她老人家。

“老妈，无论如何都不能出门呀！ "麻利锋下卡点后急急忙忙赶回家，母亲趴在客厅的窗台上看着外面，他进门也没搭理，麻利锋从母亲的视线角度看去，正好有三个垃圾箱，“正在投情爆发期，您的身体又那么弱。”

“我没糊涂，电视里天天在将。你也要小心点，小杰真的不能回来了？在武汉没人管咋办呢。” 母亲依然没有回头，神情十分失落。

“肯定不能回来的，快三十岁的大小伙子还要怎么管？昨天不是给您打电话报平安了吗？您不用担心。我天天上卡点，可比您孙子辛苦多了。”

“妈知道你们辛苦，要不我才不在家闲坐着，没感染上病毒还坐出毛病来了呢，中间那个垃圾箱里扔进去两个牛奶箱，还有一一”

“哎呀妈，看在我苦口婆心饿着肚子说了半天的份上，就算是人家把金条扔进垃圾箱，您电不能下去检，太危险了。”麻利锋把母亲架到了沙发上，有些急赤白脸，母亲却笑了。

“赶快回去吃你的饭，我又不是小孩子，你比社区那几个女人的话还多，不放心的话，你干脆把老娘绑起来，让我等死算了！”母亲的脸沉了下来。

麻利锋登时泄了气，快快地走了。再强硬下去把母亲惹毛了，还真不好收场，安葬了父亲后，他就建议母亲搬过去跟他一起住，母亲说死也要死在自己家里，动员了好几次也不听。

“老太太已经出小区了，我和门口的社区工作人员怎么劝都不听，你赶快回来吧，”麻利锋昨天没说通母亲，平上出门前就叮嘱老婆一定要过去盯着，果然时间不长老婆就打来电话抱恐，“非要去超市不可，买啥我替她去买还不行么，”

麻利锋头疼了：“唉， 就让她出去一次吧，五六天没--”

“你以为你是警察就可以让家里人随意进出？老太太真要出了事你负得起责吗？”麻利锋话没说完，老婆开火了。

麻利锋刚赶到小区大门口，就见母亲戴着口罩从不远处走来，身后跟着两个超市的工作人员，推着装满牛奶、方便面的小推车。母亲冲他欢乐地挥着手，麻利锋憋着一肚子气，大声冲母亲嚷嚷：“不让您出门就是不听，尽给人找麻烦！”

“他们几个整天守在小区门口很辛苦，我就是想给他们买点吃的喝的。”母亲轻声细语地说。

社区人员愕然，一时不知说什么好，其中一位年轻的没忍住，眼圈红了。

“老妈，您做得对！”回到家，麻利锋帮母亲脱大衣，在右边的衣兜里发现了一张工商银行的回执单，是母亲给武汉捐助了四万元的凭证，时间正是今天，超市旁边就有工商银行的营业点，麻利锋悄悄塞回去，转身给母亲竖起了大拇指。

母亲笑得像正午的阳光那般灿烂。

同温同压下，0.3mol 的氧气跟 0.2mol 的臭氧的质量比是，它们所含原子个数比是，体 积比是；将上述气体混合，所得混合气体的平均摩尔质量是。

常温常压下，用等质量的氢气、甲烷、氧气、二氧化碳四种气体分别吹出四个气球，其中气体为甲烷的是（　　）

            

设为阿伏加德罗常数的值。下列有关叙述正确的是（   ）

Was it because Jack came late for school Mr. Smith got angry?

下列叙述正确的是（　　）

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

How to Be Confident

    We are all human and have weaknesses. Even if your physical appearance or social skills aren't what you wish they were, that doesn't have to stop you from being confident.

    *Make a list of special talents you have, or things you do that are good—morally（道德上） or otherwise. It doesn't have to be a specific skill；it can be an approach or an attitude that you hold through life. Are you very patient with people? Do you always see the humorous side of things? Are you always there for your friends?

    When you feel strongly about something, speak loudly and clearly and make eye contact with people. People will judge you all the time, and usually they'll misjudge you anyway, so why bother trying to live up to their opinions at all?

    *Take care of yourself. Eat a healthy diet and get enough exercise. Don't abuse your body, don't overload it, and don't deny it any of the things it needs. At the same time, don't obsess(沉迷). Those things are only band-aids(权宜之计） and make-up. Confidence comes from within. In order to be confident, you must value yourself and understand that your well-being is important.

    *Improve your posture. Don't drop your shoulders. Make sure that your back is straight, your shoulders are square, and your chest sticks out slightly (but stay loose, otherwise you'll appear stubborn （固执的）and nervous). Good posture also helps with deep breathing, which helps with feeling calm and relaxed.

A. Here's how to believe in yourself. B. But smiling at yourself in the mirror helps you to love yourself, thus making you a bit more confident. C. Buying all the moisturizers (润肤霜) and creams will not bring you closer to who you want to be. D. It is surprising how powerful the simple step of taking action can be. E. Do you always stay calm, cool and collected, even in hurried situations? F. Having good posture can actually make you feel more confident. G. Know that you have important things to say and do.

Mike bought an old car cheaply，cleaned it up and sold it at a ______．

下列有机物的结构简式，错误的是（　　）

下列说法正确的是(     )

（1）​的分子式为　 　；

（2）写出同时满足下列条件的链状同分异构体的结构简式：　 　．

①核磁共振氢谱有2个吸收峰　     ②能发生银镜反应．