Busy _______ he was, he managed to spare some time to help plan the project.
A. while B. although C. as D. when
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
