题目

A computer can do a lot of work.The police use computers.They save all information on the computer.So the police can often check the information.And they can also visit some websites and get more information to catch criminals(抓捕罪犯)on the Internet.Scientists(科学家)today have computers for their work.They can do their work easily and quickly with the help of computers.Today in many schools，there is a computer room.Children can have their lessons with computers.For example，computers give questions on the screen of the monitor in front of the children and the children answer them 壮苗先壮根，植物根吸收水分和无机盐的主要部位是 （     ）。 A．根冠B．分生区C．伸长区D．成熟区