center
| A．ocean | B．decide | C．cause | D．socialist |
You may imagine what great difficulty I had ________ complicated ideas in simple English.
| A．expressing | B．to express | C．expressed | D．express |
The incomes of skilled workers went up. ________，unskilled workers saw their earnings fall.
| A．Moreover | B．Therefore | C．Meanwhile | D．Otherwise |
The further falling of the stock market as reported today has ________ a fresh wave of selling.
| A．given off | B．set off | C．put off | D．got off |
I'm interested in a single room. Do you have any ________？
| A．convenient | B．available | C．possible | D．personal |
I ________ on a sofa because my grandparents have been here to spend the weekend.
| A．slept | B．was sleeping | C．have slept | D．am sleeping |