for his expert advice, John is often asked to help others with their personal affairs.
| A．Having known | B．Being known |
| C．Known | D．Knowing |
34．The old saying that you should live each day_________it was your last is a nice view.
| A．only if | B．even if | C．as long as | D．as though |
33．The information________in the documents proved that my husband had been out of town in his car that day.
| A．included | B．to include | C．include | D．include |
32．Many experiments_____before the research team was able to get the exact data to carry on project.
| A．have done | B．had been doing | C．had been done | D．have been done |
31．Either you or on of your students________to attend the meeting that is due tomorrow.
| A．are | B．is | C．have | D．Be |
30．When he came back, he found the bag he had________over the seat was gone.
| A．left to hang | B．left hanging | C．to leave hung | D．to leave hanging |