Many strange new means of transport have been developed in our century, the strangest of _______ being perhaps the hovercraft(气垫船).
Busy _______ he was, he managed to spare some time to help plan the project.
The maths teacher demanded that all the students _______ the examination paper within one and a half hours.
You must keep it _______ in mind that education is the first productivity.
This word is wrongly spelt;a letter is _______.
It makes _______ big difference to keep calm when giving _______ first aid.