She offered a (an) ______ 500 yuan for the return of her lost wallet because there are many important things like ID card and keys in it.
| A．prize | B．award | C．charge | D．reward |
Personally, the job as a teacher _____ be challenging, for I sometimes _____ deal with some smarter but less diligent students.
| A．can; have to | B．may; can | C．has to; may | D．ought to; must |
Nowadays, _______ cars are more and more popular.
| A．electronic | B．electric | C．electrical | D．electricity |
I don’t know why he ________ in the middle of a sentence.
| A．broke off | B．broke out | C．broke down | D．broke up |
College graduates are offered lots of available jobs, ______, I believe, they can fully demonstrate their knowledge and competence.
| A．where | B．which | C．that | D．what |
Scientists also have no idea how long it will be before all wild animals in the cages _____.
| A．should be set free | B．will be set free | C．are set free | D．would be set free |