Many difficulties have___as a result of the overuse of coal.
| A．risen | B．arisen | C．raised | D．arose |
It’s important to write these goals down______ merely think about them.
| A．more than | B．rather than | C．other than | D．less than |
Regulations _____ that students attend at least 90% of the lectures.
| A．demand | B．ask | C．require | D．request |
It’s ten years since the scientist ___on his life’s work of discovering the valuable chemical.
| A．made for | B．set out | C．took off | D．turned up |
Although there are no classes in the afternoon now, no student ______ go out of school without the head teacher’s permission.
| A．will | B．must | C．may | D．shall |
Though _______ money, his parents managed to send him abroad.
| A．lacked | B．lacking of | C．lacking | D．lacked in |