几道英语选择题 请帮选择下 说下原因 谢谢

几道英语选择题 请帮选择下 说下原因 谢谢
[1]Is it necessary that he_____the examination?
[A] takes
[B] has to take
[C] must take
[D] take
[2]It is strange that he _____ you this.
[A] would tell
[B] should tell
[C] had told
[D] has told
[3]What you need is more ______ . Don't always do your______at your desk.
[A] exercise ; exercise [B] exercises ; exercises
[C] exercises ; exercise [D] exercise ; exercises
填空
he is not a pilot, but he wishes he____(be)