He's got himself into a dangerous situation ____ he is likely to lose control over the plane.

A.where B.who
C.while D.why
答案选A,为什么??我总觉得应该填that，难道不是同位语从句吗？？

Alec asked the policeman ___ he worked to contact him whenever there was an accident.

A.with him B.who
C.with whom D.whom
为什么选Ｃ，to contact him 中的 him 是指谁啊？？

that应该也可以不过这是选择题。where 指代a dangerous situation ，虽然“a dangerous situation ”不是实际意义上的地名但前面有个into ，把它假想成地名也行。
with whom he worked就是whom he worked with，to contact him 中的 him 是指the policeman 。