求几道英语选择题

求几道英语选择题
The scientists wanted to keep people ________ about the breakthrough in their experiment.
A.inform B.informed
C.informing D.to inform
When I first arrived in Japan,I was surprised ________ the way people greeted each other.
A.of B.to
C.with D.at
Not until that day ________ the importance of good manners in a job interview.
A.did I realize B.I did realize
C.I have realized D.have I realized
The market economy is quickly changing people’s idea on ________ is accepted.
A.that B.which
C.what D.how
要详解