Nick is a 28-year-old Australian man, which life is very difficult because he born without arms or legs.  Some people used to make fun of him and said he looked like a monster. Doing normal things seemed impossibly to him. However, Nick never gave up, and after many failures, he finally learn to swim, fish and even surf. Most surprising, he completed university and earned the two degrees. Now he is the CEO of two company.

When asking about the secret of his success, Nick’s answer is:  Attitude is altitude. To him, nothing is impossible if you has enough determination to overcome difficulties. He thinks a positive attitude is the key of success.

房地产市场调查的一般内容应涉及( )。

A．供给调查

B．需求调查

C．价格调查

D．产品调查