Bad habits, ______ formed(形成), are difficult to give up.
| A．and | B．once | C．for | D．but |
The good thing about children is that they _____ very easily to new environments.
| A．adapt | B．appeal | C．attach | D．apply |
_____ in thought, he sat at the edge of the bed, with his eyes _____ on the letter in his hand.
| A．Lost; fixing | B．Losing; fixed | C．Lost; fixed | D．Losing; fixing |
His mother looked very tired，for she _____ the house herself all day.
| A．had cleaned | B．has been cleaning | C．had been cleaning | D．has cleaned |
Having worked for as long as ten hours, the young man lay on the ground, _____.
| A．tiredly and hungrily | B．tired and hunger |
| C．tired and hungry | D．tiring and hungry |
My decision _____ to be a good one .
| A．to be proved | B．prove | C．proved | D．is proving |