A．It cannot be completely proved or disproved.
B．It contradicts most of the evidence he has collected.
C．It is the most valid theory of thinking at the present time.
D．It explains adult behavior better than it explains child behavior.
A．Teaching is not a highly valued profession in society.
B．She may change professions in order to earn more money.
C．The reason why she is a teacher has little to do with her salary.
D．More people would become teachers if the salary were higher.
A．It is a means to a productive life.
B．It is so difficult for people to attain.
C．It is valued for its own sake by all people.
D．Most people agree about what happiness is.
A．Fame cannot be obtained by all people.
B．Fame does not last forever to some extent.
C．People cannot share their fame with other people.
D．Fame cannot be obtained without help from other people.