I encountered a question in my JLPT n1 practice book , and I got really confused because I was sure my answer was right but when I look at the answer sheet the answer is really far from what I have learned so far.
the question was
その日、私はホームに入ってきた電車に飛び乗った。ところが、電車は反対方向に走り始めた( )。
私は電車の行き先を確かめなかったことを後悔した。
1.ではない
2.ではないか
3.のではない
4.のではないか
my answer was 4 but it says on the book its 2. Up until now I know that I have to put の after verb+た or verb +る in order to place ではないか.
and the sentence "私はホームに入ってきた電車に飛び乗った。" really confuse me Does it mean " I took the train that just arrived" ?
can someone help me with this one?