The local government in Shenzhen has recently passed a new regulation forbidding supermarkets and stores to _______ free plastic bags to shoppers, in order to protect the environment.

Life isn’t meant to be easy and you have to _______ some pain to 1earn the skills to move forward. 

Of all the books on the shelf,        is of any use for improving our practical skills of survival in the competitive world.

---- Dad, I have been appointed as manager of our company, but I am worried about it.--- Why worry? Increased responsibility can ___________ your best qualities.

We already have ______ pencils, but we need two ______ pens.