He always talks _______ he had been to outer space.
| A．like | B．as if /though | C．because of | D．as |
My sister______ the League last month and she has decided to ______ the activity to help the aged next week.
| A．joined; join in | B．took part in; join | C．joined; attend | D．joined in; join in |
--- What did he say? ---- He said he ________ the sentence in his own words.
| A．was considering to explain | B．considered how to explaining |
| C．would consider to explain | D．was considering explaining |
I have no doubt in my mind______ they will be glad to see me.
| A．if | B．whether | C．that | D．about |
Eric received training in computer for one year, _______ he found a job in a big company.
| A．after that | B．after it | C．after which | D．after this |
With the help of high technology, many new substances（物质）______in the past years.
| A．discovered | B．have discovered | C．had been discovered | D．have been discovered |