It is essential that students should not be limited to their classroom and should _______ their knowledge to social life.
、Martha Berry was named one of _____ women in the United States.
—What made ber so sad? —______a good chance to go abroad.
A professor of biology gave a talk to more than 1000 students on elephants living conditions and the dangers _______ them.
—It has rained for a day. What timely rain! _____________.