For better sound effects, he was asked to speak ______ the microphone during the whole process.
The reason why Daisy eats so little is that she is _________ a diet and she is trying to _______ weight.
-Hello, Mr. Wang. Must we wear the school uniform tomorrow?-You ___________. Only on Mondays. Tomorrow is Tuesday.
The Curies were ___________ the Nobel Prize for their great contributions to science.
-Why haven’t you posted the letter?-I __________ to but I forgot about it.
Often he _________ sit for hours doing nothing at all when he was in low spirits.