—Which of the two pens are you going to buy?—I’ll buy _____of them, so I can give one to my friend.

 – You have tried on several shirts.-- Sorry to take up too much of your time. But _______of them look good on me.

I was told that the water of the Ganjiang River is much cleaner than ____ of the Xiangjiang River.

_____ is known to all that the Amber Room belongs to the Russians.

--Mom, Bill is coming to dinner this evening.-- OK. Let’s give him         to eat.