The teacher told us to remain silent unless _______.

What has Tom been doing recently?-I don’t know, ____care.[ ]

Yesterday morning he got up earlier than________， for it was not a(n)________day.[ ]

____ are new here. Let’s help ____.—OK.

The engineof the ship was out of order and the bad weather _____ the helplessness of thecrew（船员） atsea.