Modern medicine is developing quickly and now most eye problems _________ be cured.
can
must
should
need
Would you like to drink milk? Thank you, but just_________
He________go to bed_______he finished his homework.
Eating________vegetables and less meat can help you to keep in good ________
The story is so ________that all of us are_______in it.
-------.__________is he staying? ------- For a month.