Su Hua is studying at Cambridge,UK.She has bought a bicycle and is worried about security(安全).Her friend,Kate,found this article and sent it to her.

Introduction A   lot of crime is against bicycles.About 150 000 bicycles are stolen every year   and most are never found.You can prevent this happening by following a few   careful steps. Basic   Security Do   not leave your bicycle in out-of-the-way places.Always lock your bicycle when   you leave.Secure it to lampposts or trees.Take off smaller parts and take   them with you,for example lights and saddles(车座). Locks Get   a good lock.There are many different types in the shops.Buy one that has been   tested against attack.Ask for a recommendation from a bike shop. Marking Security   making your bike can act as a deterrent to a thief.It can also help the   police find your bicycle.It should be clearly written and include your   postcode and your house or flat number.This will provide a simple way to   identify your bicycle. Registration There   are a number of companies who will security mark your bicycle for you.They   will then put your registration number and personal details on their computer   database.Then if your bicycle is found it will be easy to contact you. Finally Keep   a record of the bicycle yourself:its make,model and registration number.You   can even take a photograph of it.This will prove the bicycle belongs to you.

1．	Which part of the text gives you information on how to lock up your bicycle when you leave it?. A． Locks. B． Marking. C． Registration. D． Basic Security.

2．	The underlined phrase "act as a deterrent to a thief"means. A． help you recognize your bike B． help the police find your bicycle C． stop someone stealing your bicycle D． stop you worrying about your bike

3．	The article advises you to keep a record of your bicycle. A． in the bike shop and your computer B． in a police station and a security company C． in a security company and your university D． by yourself and in a security company

4．	The main purpose of this article is. A． to tell you what to do if your bicycle is stolen B． to suggest ways of keeping your bicycle safe C． to give you advice on where to buy a good lock D． to say why you shouldn't keep your bicycle in a quiet place