They are not aware of the reasons _____ people are unwilling to discus insurance.
A. when
B. where
C. why
D. how
John is strongly convinced that extra time spent studying now will _____ in the future.
A. show off
B. set off
C. pay off
D. take off
It is typical of students to stay up _____ deep into the night for the final exam.
A. to read
B. having read
C. to have read
D. reading
只能用于单一目标研究的老七种工具是( )11-277
A. 因果图
B. 分层图
C. 调查法
D. 直方图