This street is very crowded at this time of day.You have to be very cautious while ______.

Sandra failed to pass the exam.— __________ Nobody works harder than shedoes.

What do you think of his opinion?-None has given me ________ piece of advice，so I will never take it.

Look at the flowers I gave you last month.They are dying! do you water them—Sorry,I forgot to water them.

Hardly _ when they realized that it was too late to catch the last train．