Amy usually ________ from school, but today she goes home by bike.

Which is the biggest number of the four— ．

Do you have Justin Bieber’s CDs —Sorry, they ____. But we will get some more next week because they ____ .

The danger of HINI was real, especially in the beginning,_____little was known about the new disease[ ]

My father and my mother have been married for 30 years, and never once ____ with each other.[ ]