In recent years much more emphasis has been put ______ developing the students' productive skills.

A．Tehran’s view on its own nuclear weapons.
B．the debate on Iran’s nuclear weapons.
C．the idea of the U.S. and Europe about Iran.
D．the exports’ disagreement on nuclear weapons.

A．When we are sure about what we are looking for, we will understand the whole human history.
B．No other culture is advancing as the human culture.
C．As long as the group forms a culture, they may have history.
D．It will be impossible to find the beginning of the human history.