28. It is only when agriculture is fully developed___________industry can have abundant materials and markets.
| A．that | B．when | C．before | D．Until |
— Are you going to the ball tonight? —It’s too late now. How I wish ___ about it earlier.
| A．I’ll know | B．I’ve known | C．I know | D．I’d known |
_____ the fog, you would find the beautiful tower in the distance easily.
| A．Had it not been for | B．I at were not |
| C．If it had not been for | D．Were it not for |
Without the air to hold some of the sun’s heat, the earth at night ___, too cold for us to live.
| A．would be freezing cold | B．would be frozen cold |
| C．would be freezing coldly | D．can freeze coldly |
. These sheets I’ve bought ___; they’re too short for the bed.
| A．is a cheat | B．are a cheat | C．is cheats | D．are the cheats |
It was ___ cash that prevented me from joining you at lunch today.
| A．lack of | B．the lack of | C．lacks of | D．a lack of |