When you import a file into imovie the top and bottom get cut off what do you do?

Ok, so basically what you do is you selecta all of the clips in the project. Then press "C" or go to help then type in "crop" and the second one should say "ken burns, cropping, etc." click on that one. Then click "FIT" in the top left corner of the video. Then it will show the whole file!!!