You must be very tired. Why not a rest

Kate’s little brother kicked the ball to the river; she took great trouble to get in _______the river

下列各句中划线成语使用正确的一项是（ ）

Will you give me a hand I have some trouble_______ the scientific problem.—Don’t worry. I’ll try my best to help you _______.

for the free tickets,I would not have goneto the film so often.