Senior 3 high school students should be given enough sleeping time, ____________ they are busy preparing for exams to enter college.
He looks very tired . He ____ to bed too late last night .
____ the bike Smith had stolen ?
The girl was frightened by the thief , and she stood there without ____ speak .
Why did you keep it a secret from me ? I ____ about it .
— You ought to have called her yesterday . — Yes , I know I ____ .