理工类考试辅导：完形填空person walks
When a person walks， the movement of his head， trunk， hipbones and limbs are all reflected in changes in his body. A computer 1 these changes into a database. Later， the computers can 2 identify him according to these changes. This is a new biological identification method and it can quickly identify an examinee 3 disturbing him. Its especially suitable for use in airports and supermarkets.
Everybodys voice is 4 。 When a persons voice is recorded by an instrument， its voice frequency spectrum is called his sound print. Like a fingerprint， everybodys sound print is different. How can computers 5 his sound？ First， his voice is recorded， which allows the computers to become familiar with his voice. It will then turn his sound characteristics into a 6 of digits. These digits represent the frequency， pitch and rhythm of the person’s voice. These are the 7 on which the computers can distinguish1 his voice from 8 。
When that person needs to be identified， after he says only one word or two， the computers can identify him. The computers can even identify sounds coming 9 the wires. This will provide a 10 guarantee to electric banks and electric purchases.
We often bring ID cards2， work cards， or driver licenses with us to prove our identity. If all these cards are forgotten or lost， how can we prove 11 we are？ In fact， its not difficult to prove whom you are， because your body 12 has identifying markers. Some are physiological features， such as fingerprints， sounds， facial types and eye color. The computer can help to identify you. Suppose your features have already been stored in the database3. To identify you， we have to take your picture with a camera and send it to a computer for 13 。 First， the computer needs to reposition this picture according to the position of your eyes4， and then starts to read the message of your physiological features such as the 14 of your pupil5 to the whites of your eyes6 and the shape of his nose. Next， it seeks matching records from the database. Finally， it makes a 15 。
词汇：
hipbone n. 股骨 pitch n. 音高
Limb n. 肢体 license n. 执照
database n. 数据库 fingerprint n. 指纹
spectrum n. 频谱 reposition v. 改变…位置
digit n. 数码，数字
注释：
1. (basis) on which the computers can distinguish：在这个基础上，电脑能区分…… 。 前面带有介词的关系代词which引导定语从句，修饰basis.
2. ID cards：身份证。ID = identity
3. Suppose your features have already been stored in the database：假定你的特征已经储存在资料库里。 Suppose your features have already been stored in the database 可以理解为 Let us suppose your features have already been stored in the database.
4. reposition this picture according to the position of your eyes：按照你的眼睛的位置重新调整照片的角度
5. pupil：瞳孔
6. whites of your eyes：你的眼睛的眼白
练习：
1. A) checks B) stores C) revises D) modifies
2. A) nearly B) approximately C) roughly D) accurately
3. A) without B) with C) for D) in
4. A) identical B) similar C) unique D) sole
5. A) hear B) understand C) distinguish D) record
6. A) series B) package C) line D) pair
7. A) origin B) cause C) reason D) basis