如图所示，A，B两物体同时从光滑斜面的顶点由静止开始下滑．已知斜面倾角α＜β，那

If you think texting(发短信) while walking is dangerous, just wait until everyone starts wearing Google's smart, Internet-connected glasses. These glasses can do anything you now need a smartphone or tablet computer(平板电脑) to do —and then some.

In Google's video, a guy wearing the "Project Glass" is shown getting subway information, making an appointment with a friend for coffee and showing the directions in a bookstore, all with the help of the glass. It ends with him playing an instrument for a woman and showing her the sunset through a video chat.

The "Project Glass" Google displayed have a sleek(光滑的) wrap-around look and appear nothing like 3-D glasses. In development for a few years, the project is the idea of Google X, the online search-leader's secret department that produced the self-driving car and could one day send elevators into space.

Google posted the video and short blog post about “Project Glass” on April 4^th, asking people to offer feedback(反馈) through its Google Plus social network. By April 5^th, about 500 people did, voicing a mix of amazement and concern about the new technology. What if people used it in cars and could not concentrate on driving? What about the effect on(对……有影响) your sight of having a screen so close to your eye?

Some asked for the glass, but Google isn't giving those out just yet. The company didn't say when normal people can expect to get their hands on a piece of Project Glass, but going by how quickly Google will come out with new products, it may not be long. Enderle said that it could be about six months to a year before wide tests are coming, and a year or more for the first version(版本) of the product.

小题1: This passage mainly talks about         .

A. an invention                      B. a video                      C. Google

小题2:The          of the “Project Glass” is not mentioned in this passage.

A. shape                           B. inventor                    C. price

小题3:If you want to buy such a piece of glass, you should wait at least for       .

A. a year                          B. 6 months                     C. 3 months

小题4: We can’t use the glass to         .

A. communicate with others

B. keep away from the sun

C. get information

小题5: Which of the statements is TRUE according to the passage?

A. The “Project Glass” looks like 3-D glasses.

B. Many people think that the glass may help a lot while driving.

C. Some people worry that the glass will be bad to our sight while wearing it.

该表为我国自1990年以来城镇居民家庭恩格尔系数的变化情况。（7分）

注：目前联合国规定的标准：恩格尔系数在59%以上为绝对贫困，50%—59%为温饱水平，40%—49%为小康水平，20%—40%为富裕水平，20%以下为极度富裕。

（1）请写出恩格尔系数的计算公式（1分）

（2）上表反映了什么经济现象？造成这种变化的主要原因是什么？（6分）

对于无烟煤和烟煤相比，其容积热负荷q_V值应取（）些，截面热负荷q_F应取（）些，若采用直流燃烧器时应采用分级配风型。

《特种设备安全监察条例》规定：特种设备作业人员在作业过程中发现（）或者其他不安全因素，应当立即向现场安全管理人员和（）报告。

在深圳证券交易所证券交易的托管制度下，投资者在一家证券营业部买人证券后，可以在任一家证券营业部卖出该证券。()