_______ a certain doubt among to the students as to the necessity of the workA.there existed B.there had c.they had D.it existed麻烦问下 为什么D不行

It's widely accepted that young babies learn to do things because certain acts lead to _______.A.rewards B.prizes C.awards D.results a certain just missed a certain date certain be certain to do 和be sure to do 的区别we are__to win the match You wait and see .A,certain B,sure C,believe Dthought a certain什么意思 in a certain way act in a certain in a certain sense You don't have to be a hero to do certain things to compete. of course,it's good to do some practice tests but,after a certain point,you don't learn anything new.after a certain Scientists found that when certain parts of the brain were _____ we lost the ability to do certain things.A． destroyedB． damagedC． woundedD． hurt would rather _______ A.to do B.do certain certain certain a certain food怎么翻译?（a certain?） Do the twins go home by bus(同义句)Do the twins _______ a bus _______? a certain country什么意思