若事务T对数据R已加排他锁(X锁)，则其他事务对RA．可以加共享锁(S锁)，不能加X
题型：单项选择题
问题：
若事务T对数据R已加排他锁(X锁)，则其他事务对R
A．可以加共享锁(S锁)，不能加X锁
B．不能加S锁，可以加X锁
C．可以加S锁，也可以加X锁
D．不能加任何锁
题型：单项选择题
The Internet, mobile phones and iPads are part of our lives now. Technology is greatly affecting all ways of our lives, from the ways we work to the ways we play. And it even causes a number of social problems such as cloning humans.
We have had lots of technology and it has changed our lives a lot. There is no doubt that humans will continue to use more and more technology. Here are some examples of modern technology that will change our ideas and will affect our lives greatly.
Global Positioning System (GPS) (全球定位系统)
It’s a system that uses radio signals from satellites to show exact (精确的) information. It tells you where the user is on the earth in all weather conditions. It’s made up of three parts: satellites, control equipments (设备) on land and receivers.
Space Technology
Russian and American scientists have worked together for the International Space Station (ISS) for a long time. They hope the ISS will provide a long-lasting lab. Such a lab will bring humans limitless (无限的) advantages. It’s even hoped that one day space technology will take humans to their new houses in space.
Underwater Robot
Hercules is a kind of underwater robot with some high technology equipments. It will be used to search for ancient ships which were destroyed into the deep sea during their journey long ago.
The world is changing so quickly that it’s hard for us to catch up with all the new inventions because they seem to come out every month. It’s important for us to learn about new technology and the role that it plays in our lives. So we should be willing to accept modern technology, or we will fall behind the times.
小题1: can tell you where the user is on the earth exactly.
A．Satellites
B．Receivers
C．Global Positioning System
D．Underwater Robot小题2:According to the passage, which is NOT true about the ISS?
A．It has carried people to other planets.
B．It will provide a long-lasting lab for us.
C．Russia and America are working for it.
D．Humans will get a lot of advantages from it.小题3:Hercules is used to .
A．save lives in the sea
B．take pictures in the sea
C．repair the broken ships
D．look for the ancient ships in the sea小题4:From the passage, we know that .
A．the use of GPS is affected by the weather conditions
B．it’s very important for us to learn about new technology
C．it’s easy for us to catch up with all the new inventions
D．technology brings us many advantages such as cloning humans小题5:What is the purpose of the passage?
A．To help us study some new technology.
B．To tell us technology is changing the world.
C．To help solve the problems that technology causes.
D．To remind us the advantages of technology are limitless.
