题干

“新丝绸之路经济带”和“21世纪海上丝绸之路”能有效促进我国经济繁荣发展.我国是最早养蚕缫丝的国家,如图所示家蚕的生长发育过程,下列叙述不正确的是( )

A:家蚕是有性生殖方式

B:蚕丝产生于②时期

C:家蚕的发育过程比蝗虫多了③时期

D:家蚕的发育为不完全变态

上一题 下一题 0.0难度 选择题 更新时间:2017-08-22 10:02:00

答案(点此获取答案解析)

D

同类题2

阅读下列短文,从下面每小题的A、B、C、D四个选项中选出最佳选项。

    I'll tell you a secret. There's a place that gets me every time: whenever I'm there. I can't help but cry. Where is it? It's thousands of metres high in the sky, in a plane, especially when there's a heart-warming comedy on.

    Why am I admitting (承认) this now? Because I'm not alone. The British singer Ed Sheeran says he gets emotional (情绪激动的) when flying too. Also a survey carried out by Gatwick Airport in London found that 15% of men admit they're more likely (可能的) to cry during films in planes than watching at home. And 41% of men admit they often try to hide their tears in another survey by Virgin Atlantic (a British airline). In all, 55% of air travellers in the Virgin Atlantic study said they get emotional when flying. So, what's going on? A study from the Netherlands has shown that adults cry because of feelings of separation, loneliness or powerlessness. All of these are easily experienced when flying: you're far from family, often alone, and have no control over the flight.

    Another   ▲   is that when you're in a plane in the sky, there's not a lot you can do. So you are able to pay more attention to the movies you watch. Then there's the physical space. In a plane, air pressure and oxygen levels are lower, and this can affect (影响) our brain and emotions. On a flight, you may be leaving loved ones or really wanting to see them again, or you might have had a drink at a time you usually wouldn't, and if you see a scene that reflects your emotional state, without doubt it's easier for you to cry.