---- Did he come back early last night?
---- Yes. It was not yet eight o’clock _______ he arrived home.
| A．when | B．that | C．before | D．until |
. While he was investigating ways to improve the telescope, Newton made discovery which completely changed man’s understanding of color.
| A．a; / | B．a; the | C．/; the | D．the; a |
. The breakdown of the machine brought the work into a mess.
| A．relevant | B．academic | C．abrupt | D．absurd |
Hangzhou is distinguished its beautiful scenery.
| A．as | B．for | C．in | D．by |
. Don’t let yourself be by a small failure in the experiment Try again.
| A．turned down | B．cast down | C．put down | D．made down |
______________food are needed.
| A．Quantities of | B．Mass of | C．A large amount of | D．Lots of |