81. It ___________ (snow) hard now. We'd better ___________ (not go) home right now.
80. Tennis ___________ (invent) a hundred years ago.
79. English ___________ (speak) in Canada.
78. So far, many man-made satellites have ___________ (send) up into space.
77. The young trees must ___________ (tie) to the stick to keep it straight.
76. The mountain will ___________ (cover) with the trees in a few years.
75. Can the report ___________ (write)in English?
74. The Great Green Wall must ___________ (build) in the world.
73. English ___________ (speak) all over the world.
72. The English song ___________ (teach) now over the radio.