The science Festival is an occasion _____ model planes and model rockets are flown over the school grounds.
Try to spend your time just on the things you find _______.
_______ about the economic crisis that he decided to look for more information about it.
The great changes _______ have taken place _______ carrying out the economic reform in our country.
Although all of the apples _______, none of them _______ good.
—Who should be responsible for the accident?—The boss, not the workers. They just carry the orders _______.