People have always been curious how living things on the earth exactly began.
| A．in | B．at | C．of | D．about |
19. It’s quite an informal gathering ; you needn’t ______for it .
| A．dress down | B．dress up | C．dress | D．dress on |
18. I’m surprised that you should have been fooled by such a(an) ____trick.
| A．ordinary | B． easy | C．smart | D．Simple |
17. It’s known that taking exercise______your health.
| A．do good to | B．does good to | C．is good to | D．are good for |
16. He gave a ________smile.
| A．satisfying | B．satisfied | C．satisfaction | D．Satisfactory |
15. They gave a banqnet( 宴会)_____the guests from Britain.
| A．in honour of | B．in an honour of | C．in honour to | D．in honour for |