Carbon dioxide, which makes a ______ between us and the sun, prevents heat from getting out of the atmosphere easily, so the earth is becoming warmer.
| A．difference | B．comparison | C．connection | D．barrier |
--------May I take this book out of the reading room?
------No,you_________. You read it in here.
| A．mightn’t | B．won’t | C．need’t | D．mustn’t |
Studies show that people are more_________to suffer from back problems if they always sit before computer screens for long hours.
| A．likely | B．possible | C．probable | D．sure |
. I have to see the doctor because I_________a lot lately.
| A．have been coughing | B．had coughed |
| C．coughed | D．cough |
John thinks it won't be longhe is ready for his new job.
| A． | when | B． | after | C． | before | D． | since |
His first booknext month is based on a true story.
| A． | published | B． | to be published | C． | to publish | D． | being published |