46．The text is mainly about how to 　　．

A．	be a careful driver
B．	buy MTR tickets
C．	be a good passenger
D．	keep safe at home

47．People who will get on the train should 　　．

A．	wait in line
B．	open the door
C．	ask for help
D．	leave the seats

48．When you hear a"beep"sound， 　　．

A．	close the door
B．	rush onto the train
C．	get off the train at once
D．	stop and wait for the next train

49．Which picture shows the good behavior on the train according to the text？ 　　

50．The text is probably a 　　．

A．	report
B．	notice
C．	diary
D．	poem．