Not until all the fish died in the river, ____ how serious the pollution was.

_______ necessary for us _______ our environment clean and tidy.

Work starts every day at 7 a.m and goes onuntil late afternoon__________a break at midday.

Though I can’t make the model ship ____faster, the model plane can be made higher by any of the boyshere.[ ]

_________ did the students realize that they were mistaken about spiders.