【题目】It's not doing the things we like, but liking the things we have to do ________ makes life happy.
A.that
B.which
C.what
D.who

【答案】A
【解析】句意：是做我们喜欢做的事情，而不是喜欢我们不得不做的事情让生活幸福。本题强调主语not doing the things we like, but liking the things we have to do。故A正确。