某种细胞的直径是5×10^－4毫米，这个数是（ ）

选词填空阅读下面短文，从方框中选择单词，根据实际情况用其适当形式填空，使短文意思完整、通顺。每空一词，每词只能用一次。

 A man was tired of living in his small house in the country.  He wanted to sell it and buy a ____  one than the old one nearby. He tried to sell it for a long time, but____ wanted to buy it. So at last, he decided to use a house salesman. The salesman soon put a picture of the man's house on a magazine. ____  days later, the owner saw a very beautiful picture of the house, with a wonderful introduction to its gardens, on a magazine. After the house owner had read ____ the whole introduction, he at once called up the salesman and said,“I'm sorry, but I've decided not to sell this house after all. After ____  your introduction, now I know that It's just the kind of house I'm going to live in for the rest of my life.

阅读理解

　     Soon computers and other machines will be able to remember you by looking at your eyes! The programme works because everyone's eyes are different. So in the future you won't have to remember a number when you want to use a machine or take money out of a bank. You'll just have to look at the machine and it will be able to tell who you are. The eye-recognition(眼睛识别) programme is tested in shops and banks in the USA, Britain and Italy.

       Scientists are working on other systems, such as knowing you from the shape of your face or hands or even your smell! And machines can already tell who you are from your voice or your fingerprints(指纹). But eye-recognition will replace other ways of finding out who you are. It is better, because your eyes don't change as you get older, or get dirty like hands or fingers. And even twins have different eyes, so the programme can be up to 94% correct, depending on how good the technology is. In Britain, it was found that 91% of the people said that they liked the idea of eye-recognition.