—I just wonder that made Mark Twain so famous a writer.
—Of course his early experiences.
| A．it was what | B．what he did | C．how he did | D．what it was |
__________ everything a shot because you never know what is going to change your life.
| A．Giving | B．To give | C．Give | D．Given |
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 |