He is the very lecturer, __________ experience impressed us greatly at the conference yes-terday.
I try to understand __________ that prevents so many Chinese from being as happy as one might expect.
Desertification,the name for ______ happens when farmable land is turned into desert,is a growing world problem.
Some students held the view ______ surfing the Internet was good for their study.
It was believed by the ancient Egyptians that intellect was to the mind ___sight was to the body.
Since it is expected that Fed will cut interest rate again, there is no doubt ___the company will make the decision on raising the price of crude oil.