题干

下列说法中正确的是(   )

A:可以用澄清石灰水鉴别CO2、SO2.

B:硫粉在在过量的纯O2中燃烧可以生成SO3

C:NH3经催化氧化生成NO2,然后经过一系列反应可以得到HNO3

D:Cl2、NO2、NO、SO2、NH3等气体对人体均有毒害作用。

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答案(点此获取答案解析)

D

同类题1

移动互联网改变了人们的生活方式,也在快速重塑着城市居民的社交图景。

材料一:邻里相望,鸡犬相闻的美好愿景,在城市的钢筋水泥里渐行渐远。在过去的一年多,一款名为“楼里”的手机应用正试图在北京上万个小区,构建一种新型的邻里关系——社区共享。

“你有问题,我提供答案;你有盈余,我正好需要;你需要知晓,我分享所见。”由于邻里社区有天然的信任感,搭邻居的车更放心、转让二手物品时对价格没那么敏感,所以社区共享受到很多人的追捧。

材料二:北京某社区民警,通过“楼里”APP向辖区居民分享了一则“警情提示”,通报社区里发生的3起入室盗窃案,提示居民睡前关窗锁门,公布民警联络电话。随后,该社区4000多位注册用户收到楼里推送的紧急通知。

此举获得一片赞誉之声,从单向发布,到双向分享互动,在居民、警民的指尖互动中,民警的亲和力得到了加分。“楼里”不仅接入了社区民警,发布安全提示、回应报警信息,同时还接入了街道办和居委会,将政府公告、社会服务信息纳入其中。

材料三:被分享的不只是经济。中国有句俗话称“远亲不如近邻”,一位妈妈把童车、婴儿衣物等用不到的东西转让给另一位妈妈,同时交流育儿方面心得;同一个社区的大学生们在交换课本和考研资料的同时,也把自己积累的学习体会传授给他人;喜欢某一类数码产品的发烧友们凑在一起互通有无,比交易成功更难得的是为自己的宝贝找到“知己”,价钱甚至变得不那么重要……

同类题5

根据短文理解,选择正确答案。

    With all of the wonderful things life brings us, it also brings us stress. It is for this reason that I am an active supporter of mental health days.

    Although it's never good to ignore(忽视) responsibilities, sometimes it is good to unplug(拔除) from the world for a day. We eat healthy and stay active to keep us from getting sick, but sometimes we forget to care for our minds. Our minds and bodies are connected, and when only one is being cared for, the other may be suffering. It is important to try to combine self care with our lives and spend time on activities we enjoy. This helps relieve stress on a daily day.

    So, what do you do on a mental health day? The answer is anything you want. Growing up, my brother and I were allowed a few mental health days a year. We would stay home from school and relax. For him, it was playing games on the computer, while my days were spent reading or watching TV. My mental health days now include picking things up around my apartment, cooking a tasty meal, and then reading for a few hours. I completely shut myself off from work or school. To me, this is relaxing. Organize the clutter(凌乱的东西) that piles up during the week, cook the meals I don't have time to cook, and read the books that I've bought but don't have time to read.

    A mental health day is great, but only if it's supplemented(增补) with self care through the week. From my experience, if self care is not regularly provided in your week, taking a mental health day is just going to stress you out even more. But when it's needed, try hard to recognize that and take care of yourself. It will help keep you happy and healthy. A mental health day is not a day to avoid life, it is a day to recoup(恢复).