Because Michael was walking in the dark alone, he sang to ________ his courage.
| A．hold up | B．take up |
| C．set up | D．keep up |
The maths teacher demanded that all the students _______ the examination paper within one and a half hours.
| A．would finish | B．finished | C．finish | D．could finish |
You must keep it _______ in mind that education is the first productivity.
| A．mildly | B．firmly | C．tightly | D．roughly |
This word is wrongly spelt；a letter is _______.
| A．left behind | B．left alone | C．left out | D．left off |
It makes _______ big difference to keep calm when giving _______ first aid.
| A．a, / | B．/, the | C．a, the | D．/,a |
_______, the experiment will be successful.
| A．If carefully doing | B．If it done carefully |
| C．If carefully done | D．If doing carefully |