题干

我国首例“虎狮兽”2002年在“南京红山动物园诞生”,利用了雄虎的精子和雌狮卵子“体外受精” 而产生,完成这一过程需要解决的问题是:  

A:精子在体外用获能物质的处理

B:用化学物质处理掉卵黄膜便于精子进入

C:抽取精子、卵子的细胞核进行融合

D:精子入卵后进行人工处理防止多精入卵

上一题 下一题 0.0难度 选择题 更新时间:2019-07-31 11:38:22

答案(点此获取答案解析)

A

同类题5

根据短文内容,选择最佳答案。

    Some days, don't you think, "Wouldn't it be nice if the laundry would just do itself?” Self-cleaning clothes may sound crazy. But Australian researchers have found a way to make something like this possible!

    A team at RMIT University in Melbourne, Australia, found a way to put special nanostructures (纳米结构) into clothing, which can then clean the clothes. When sunlight hits the nanostructures, they break down the dirt and stains (污渍) that don't belong on your clothes.

    The nanostructures don't break down the actual clothing because cotton and the other clothing materials are too strong to be broken down. According to CNN, the researchers cover the clothing in a solution made of silver and copper (铜) nanostructures. All it takes is 40 minutes of sunlight and your clothes will look as good as new.

    So if you spill on yourself during lunch, you can step outside for a walk, and it will be clean by the time you go inside. It not only makes your life easier, but it can also be good for the environment.

    According to the US Department of Energy, the average load of laundry uses about 25 gallons (about 94 liters) of water. Water is a very important resource, so using less of it to wash clothes is better for the environment. But one of the scientists at RMIT University knows more needs to be done.

    “There's more work to do before we can start throwing out our washing machines,” said Dr Rajesh Ramanathan, “but this is a strong foundation (基础).”

    So what's the next step? Ramanathan wants to either start selling the solution by itself or convincing (说服) clothing makers to treat the clothing with the solution while clothes are being made.