Not until the early years of the 19th century____ what heat is.
| A． man did know | B．man knew | C．didnot man know | D．did man know |
The construction workers completed the bridge three months _____ time and were praised by the local people.
| A．in accordance with | B．in front of | C．ahead of | D．prior to |
A lot of revolutionaries _____ their own lives for the liberation of our country.
| A．devoted | B．sacrificed | C．contributed | D．delivered |
It’s cloudy outside. Please take an umbrella. _______ it rains.
| A．Take it easy | B．Just in case |
| C．It just depends | D．All right |
When and where to go for our holiday _____ yet.
| A．are not decided | B．have not been decided |
| C．is not being decided | D．has not been decided |
He will never tell lies, and it’s against his _______ for he’s such an honest man.
| A．rules | B．regulations | C．patterns | D．principles |