1.The population of Shanghai is more than that of Hong Kong.
more==>larger
集合名词population表示人口的"多"或"少",不用"much"或"little",而要用"large"或"small".
(楼上的乱回答..)
2.It's very nice for you to give me a chance.
for==>of
It is +adj+for sb.+to do sth.多用来形容一件事情,
It is +adj +of sb.+to do sth.多用来形容人
举例
It's very difficult for me to do it.Difficult 指事情很难
It's very kind of you to do it for me.Kind指人的品质好