Don’t bring food to the library, or your teacher will ______.

Once we discover a mistake, we should not ______ it but correct it immediately, to create better conditions for economic development.

You speak English well.Who teaches you?–Nobody.I learn it by _________.

How_______will you stay here?—Just for two days.[ ]

When was David born?—He was born________June 12,1989.[ ]