I think you’ve got to the point where a change is needed , _____, you’ll fail .

Although Linda tried hard in the exam, she did ______ than her brother. 

(2009年合肥市高三第一次教学质量检测)The police tried to get some clues from the suspect，but he remained     ．

His car ran over another in the highway! Too horrible! _____ he is safe now—that's the main thing．

 The repair work may take us a long time，but          it’s worth trying.