The little boy is dirty from head to foot because he ________ in the mud all morning.
The chairman thought _______ necessary to invite Professor Smith to speak at the meeting .
------Flight 302 to London_______ until 7:30 tomorrow morning.-----No wonder I hear so many complaints from the passengers.
When the American constitution ______into effect in 1789,it didn’t contain any words guaranteeing the basic rights of ordinary citizens.