These days the government has issued several economic policies that will ________ prosperity of manufacturing industry. [ ]

His work _________ have been completed; otherwise, he wouldn’t be enjoying himself on the beach.

It’s helpful to put students in a situation _______ they can learn how to cooperate with each other.

Smoking ________ in the forest. It may cause a fire.

You will never succeed _________ you devote yourself to your work .