RT-Supermarket _______at 9 a.m. and it ______ for 10 hours every weekend．

_____did it _____the conductor to check the tickets this morning?-Half an hour.[ ]

There are ______students in my class, twenty girls and twenty boys.

My grandmother a lot of changes in Tianjin since she came here.

______ breakfast, I usually have an egg, some bread and a glass of milk.[ ]