-Mary, how did your Math test go?-I had thought I _________, but in fact I came in the top 10% in my class.
It is still unknown_______ caused the accident last Saturday.
____ wants to stay in a hotel has to pay their own.
The experiment shows that proper amounts of exercise ,if _______regularly, can improve our health.
It is one of the funniest things ____on the Internet so far this year.
To learn English well, we should find opportunities to hear English_______ as much as we can.