69. With the guide leading the way, the visitors were able to travel through the forest not by air but _____ foot.
Giving up smoking is a slow and painful _______ for him.
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 _______.