最常见的登高脚架是（）。A、落地式B、悬挑式c、附着式D、移动式

六个袋内分别有18、19、21、23、25与34个球，其中一个袋内装的都是有裂口的球，其余五个袋内都没有带裂口的球．现在小王拿了其中三个袋，小丁拿了两个袋，只剩下那个装有裂口球的袋．如果小王得到的球数是小丁得到的两倍，那么有裂口的球是______个．

I got interested in the idea of standing desks about a year ago. The health advantages of standing instead of sitting for eight hours a day are clear, so when the company Ergotron invited me to review their WorkFit C-Mod Dual Desk, I jumped out of my chair---really.

After several hours putting the desk together, I finally got to try it out. The standing desk had a desktop that I could use for writing.

At first I absolutely loved it. Standing during the day instead of sitting was fantastic. Although I felt more tired after all that standing during the day, I knew the health benefits were worth the slight discomfort. However, after the initial novelty (新奇)of the desk wore off, I realized that I could not use it in the long term.

It was just not practical. While using the desk for a month , I could definitely foresee problems arising from using it full time.

I enjoy having a lot of things on my desk. The standing desk just did not have enough room for all of my things.

I can easily foresee awkward situations when I put that desk in an office space. When someone comes into your office, does your guest have to stand as well? If you office is big enough, maybe you have room for two chairs for you and a visitor, which is great. Yet for the ordinary worker in a small office, the standing desk creates a very awkward situation.

Additionally, the amount of money I would have to spend to replace my current workspace with a standing desk was another issue. The desks I have looked at were highly expensive.

Yes, spending the day standing can offset(抵消) many of the negative effects of too much sitting, but we humans are designed for movement. Through activity changes like taking the stairs instead of the elevator, you can easily increase the time you spend on your feet. Best of all, those options are completely free.

小题1:When the author was asked to try the standing desk out, he was ____.

A．excited

B．surprised

C．unhappy

D．uninterested小题2:When first using the standing desk, the author ___.

A．thought it was boring

B．thought it was wonderful

C．felt less tired than usual

D．felt quite uncomfortable小题3:According to the author, a standing desk ____.

A．takes up too much space

B．is suitable for long-term use

C．is cheaper than traditional desks

D．is impractical though good for health小题4:What does the author mainly tell us in the text?

A．How to use the standing desk.

B．What he does during the workday.

C．His opinion on the standing desk.

D．The advantage of the standing desk.

在卵泡生长发育中，卵母细胞周围的细胞变为方形，并增生成为：

A．卵泡内膜细胞
B．卵泡外膜细胞
C．颗粒细胞
D．卵细胞
E．黄体细胞

人工接地体在土壤中的埋设深度不应小于0．4m。

糖尿病的形成有多种原因，如下图所示①、②、③表示由三种机体免疫异常引起的糖尿病。请据图回答下列问题：

图中②所示的患病机理是（），导致胰岛素分泌减少，血糖浓度升高。