—Each boy and each girl     talking about optional courses（选修课）.—Yes! And the each     their favorite one!

—Are these your sheep ?—No. Mine _____ on grass at the foot of the hill.

 The father as well as his three children _______ skating on the frozen river every Sunday afternoon in winter.

Twenty of the students will have sports, the rest ___ studying here

There _________ an apple on the desk.