1＿＿of the accident last year,he had to lie in bed for 3 mont

1＿＿of the accident last year,he had to lie in bed for 3 months.
A.For a result B.In a result C.With a result D.As a result
2Mary has made her decision,and she is determined to__it.
A.stick to B.stick out C.stick on D.stick by
3Ever since the new schoolmaster came,the school__a lot.
A.had to change B.has changed C.will change D.must change
4.__hearing that his mother was sick,he immediately went to the hospital.
A.On B.In C.At D.From
选哪个,为什么,