It is worth considering what makes “convenience” foods so popular,and ________ better ones of your own.
I don’t think _____ possible to master a foreign language without much memory work and practice.
Work hard at your lessons, ______ you’ll fail the exams again.
He devoted all the time _____ his research .
Mr. Liu dreamed ____ a big house for his parents after they retire.
On the bus I saw a student____ I thought was your brother.