Tom drank up the whole bottle of milk, _____even a drop to his little brother.
| A．not leave | B．leaving | C．not leaving | D．not to leave |
Being exposed to loud music too much ________ caused hearing loss in some teenagers.
| A．is | B．has | C．are | D．have |
Peter was so excited _________ he received an invitation from his friend to visit Chongqing.
| A．where | B．that | C．why | D．when |
The international agreement, __________to help people kick off the habit of smoking, was signed two years ago.
| A．intended | B．intending | C．intends | D．to intend |
The fact has worried the people across the world ___________ the earth is becoming warmer and warmer these years.
| A．what | B．which | C．that | D．where |
Bob would have helped us yesterday, but he ____________.
| A．is busy | B．had been busy | C．has been busy | D．was busy |