Not until all the fish died in the river, _______ how serious the pollution is.[ ]

These problems, ________, will seriously affect the growth of teenagers and even the nation’s future.

On Sundays there were a lot of children playing in the park, _______ parents seated together joking.

The students leave school a little _____ than usual _____ Friday afternoon.

I am going to Qingdao for a holiday with my parents this summer.—–_______________!