Yoshi's Island Q&A

i cant find 4 of the red coins in level 1-7 im trying to get 100 on all levels and i have 100 on all in the 1st level except that one. I've looked and looked and looked and cannot find them.

I found the first key but cannot find the key to unlock the second door with the ghost?

how do i pass level 3-6

i have gone every where i can and still cant beat it what am i donig wrong