Is this problem ___ the teacher explained last week?

Is this problem ___ the teacher explained last week? is this problem ( ) the teacher explained last week A.which Is this problem _________ the teacher explained last week A. Is this problem ___ the teacher explained last week?A whichB 34.Is this the problem _______the teacher explained last wee Is this problem （ ）the teacher explained yesterday Is this problem （ ）the teacher explained yesterday? 一个英语单选题,Is this problem _____the teacher explained last weak 关于which的语法This problem is which the teacher explained yester This is the bike ___ I bought last week填空 This is the way ___ he solved the diffcult problem. This is the restaurant___we enjoyed our meal last week