The headmaster was dismissed three months ago.The post is too important to leave　　 any longer,especially before the college entrance examination.

6. As there is less and less coal and oil, scientists are exploring new ways of making use of   energy, such as sunlight, wind and water for power and fuel.

—How’s your new babysitter? —We ______ ask for a better one. All of our kids love her so much.

It’s______to borrow money from your mother to pay back your debt. That’s just robbing Peter to pay Paul.

She’s so ______ that no one can please her.