We ____ last night, but we went to the concert instead. A must have studied B might study C should have studied D would study
I ________ with my grandma because my parents have gone abroad for further study.
How can they learn much ________ they spend so much time playing computer games?
Cars do cause us some health problems, in fact, far more serious ________ than mobile phones do.
After ________, the litter girl was depressed and kept silent all the day.
The scientist corresponds with colleagues in order to learn about matters ________ to her own research.