一道语法填空

一道语法填空
When you are in England you must be very careful in the streets 1_________ the traffic drives on the left.Before you cross a street you must look to the right first 2__________ then the left.In the morning and in the evening when people go to or come from 3__________,the streets are very busy.Traffic is most 4________ （danger） then.
When you go by bus in England,you have to be careful,5_________.Always remember the traffic moves on the left.So you must be careful.6_________ （have） a look first,or you will go 7_______wrong way.
In many English cities,there are big buses 8_________ two floors.You can sit on the 9_________ （two） floor.From 10_________ you can see the city very well.It’s very interesting.
第7个空填什么,a还是the,