单选题 _ makes mistakes must correct them.

单选题 The problem is _ to take the place of Ted.

单选题 It worried her a bit _ her hair was turning grey.

单选题 It is no longer _.

单选题 It's uncertain _ the experiment is worth doing.

单选题 The fact _ she works hard is well known to us all.

单选题 _ is going to do the job will be decided by the Party committee.

单选题 You are saying that everyone should be equal, and this is _ I disagree.