One should keep ________ promise.
—You didn’t invite Mary to the ball?—____ her, too?
I only know we will have a League meeting, but I have no idea when _________ it.
______ is known to all, the earth travels round the sun once every year.
Many people in China are ________ a “Hope Project”, helping poor children to get compulsory education.
But for the storm, we __________ a pleasant journey, but had to turn back halfway.