Train services are usually ________ and run regularly every day. [ ]

19. They________a lot of suggestions for improving the workers’ living conditions.

re people in Shanghai have been ________ to beinfected with the deadly H7N9 bird flu, local authorities said on Sunday.

____-Maria will come to the partymakes no difference.

For our middle school students, some courses are compulsory, while others are ______. [ ]