急求三道句型转换1、How many people are there in China?转化成( )the popul

急求三道句型转换
1、How many people are there in China?
转化成( )the population of China?
2、I find that is impossible to get there on time.
转化成 I ( )impossible to get there on time.
3、He is very happy to know that his father will come back.
转化成He is very happy ( )that his father will come back.