The stubborn young man did not follow the advice that he （）on his behavior since he refused to believe he had done anything wrong.

单项选择题Variables such as individual and corporate behavior （）nearly impossible for economists to forecast economic trends with precision.

A．make
B．to make it
C．it makes
D．make it

单项选择题In this country it is required that anyone who has recently come here （） taxes.

A．will have to pay
B．would have to pay
C．have to pay
D．has to pay