By the time he was twelve, Edison _______ to make a living by himself.
| A．has begun | B．began | C．had begun | D．had been beginning |
China’s economy expanded 8.1 percent in the first quarter from a year earlier,___the slowest pace in almost three years.
| A． marking | B． to mark | C． having marking | D． marked |
So diffcult____it to fit in at school that she decided to drop out.
| A．found she | B． did she find | C． she found | D． she did found |
Wait for a while .I will get you something to drink.
Don’t ____.I have to leave now.
| A． worry | B． interrupt | C． disturb | D． bother |
This is the second time I____a call from that telephone number.
| A． have received | B． had received | C． received | D． receive |
AsＩ ____the house ,I noticed a light on upstairs, which made me quicken my pace towards the doorway.
| A． left | B． passed | C． entered | D． approached |