Smartphone ,poor sight Look around and y

题型:阅读理解

问题:

Smartphone ,poor sight

Look around and you’ll see people busy on their smartphones. Smartphones do make our lives easier . But have you ever thought about what they mean to you eyes?

According to a study ,half of British people own smartphones and they spend an average of two hours a day using them . There has been a 35% increase in the number of people in the UK who suffer from shortsightedness since smartphones were introduced there in 1997.

Staring at smartphones for long time gives you dry eyes. When looking at something in the distance ,your eyes automatically blink a certain number of times. However ,when you look at things closer  to your face ,the blinking slows down . This reduces the amount of tears and causes discomfort in your eyes. Another bad habit is using  smartphones in dark rooms before going to sleep . If you look at a bright screen while your pupils become larger ,too much light enters your eyes. This can do harm to the eyes and cause a disease called glaucoma.

While you’re probably not going to stop using to your smartphone,there are a few things you can do to protect your eyes. Hold  your phone at least 30 continues away from your eyes when using it. Take a break every hour and try the following :look at something at least five meters from you and then focus on the tip of your nose. Repeat this several times. It should reduce the discomfort in your eyes.

考点:健康环保类阅读
题型:阅读理解

写出两组直角三角形的三边长(    )。(要求都是勾股数)

题型:阅读理解

第39-44题为套题20世纪70年代末,我国开始了由计划经济向市场经济转变的经济体制改革,以经济建设为中心,对外开放。这场改革涉及社会经济的各个层面,对中国社会产生了深远的影响。

国务院于2005年底发布实施的《促进产业结构调整暂行规定》指出,产业结构调整要各地结合本地区产业发展实际,制定具体措施,以():①合理引导投资方向;②鼓励和支持发展先进生产能力;③限制和淘汰落后生产能力;④防止盲目投资和低水平重复建设;⑤切实推进产业结构优化升级。

A. ①②③④

B.①③④⑤

C.②③④⑤

D.①②③④⑤

题型:阅读理解

(2m1七•重庆模拟)A、B、C、D、f、F、G、H、I都是初中化学学过的物质.其中B为红色固体单质,D为混合物,f、H均为黑色固体,F是一种无色气体.它们之间有如图的转化关系(部分生成物已省去).

(1)A、G的化学式分别为______、______.

(2)B→H的反应类型为______.

(3)写出F→f,C→D的化学方程式______、______.

题型:阅读理解

机体第一次生长发育高峰期是几岁之前()

A.5~6岁

B.10岁左右

C.12岁左右

D.14岁左右

E.18~20岁左右

题型:阅读理解

电影

更多题库