We have various summer camps for your holidays. You can choose _______based on your own interests.
The old man turned his business over to his younger son, ________made his elder son discouraged.
Stand _____ you are, and I will come and help you.
Keep away from the dog , _______it will bite you.
He made up his mind to devote all he could _____ his spoken English before going to college.
We live in a society ______ there is a great deal of debate about competition.