Boats in this area are ________ in order to keep the dolphins safe．
A.prohibited from enteringB.preventing from enteringC.stopped to enterD.kept from entering into在线课程A
本题考查了“禁止……做某事”的几个表达方法。prohibit…from doing/prevent…from doing/stop…from doing/keep…from doing。enter是及物动词，不和into连用。