In this section, we will briefly describe possible ways of reducing the costs and risks __________ in doing this.
| A．involving |
| B．involved |
| C．to involve |
| D．being involved |
As there is less coal and oil, scientists are exploring new ways of making use of _____ energy, such as sunlight, wind, and water for power and fuel.
| A．primary | B．alternative | C．instant | D．unique |
— Look! Someonethe laptop.
— Well, it wasn’t me. I didn’t do it.
| A．has repaired | B．is repairing | C．had repaired | D．was repairing |
—Mum，can I go on a holiday with my classmates this summer vacation?
—OK．Youhave a chance if you get along well with your studies．
| A．could | B．shall | C．might | D．must |
You had better _____ some time every day for sports so that you can keep yourself energetic.
| A．put away | B．take up | C．set aside | D．give out |
Sam has been appointed _______ manager of the engineering department to take ____ place of George.
| A．/,/ | B．the,/ | C．the; the | D．/, the |