121. Forest help to keep water from ___________ (run) away.

120. In about 600 years, we will hardly have enough space _________ (stand) in on the earth.

119. My job is ___________ (feed) the animals.

118. In the country, he can hear birds ___________ (sing) and sheep ___________ (bleat)

117. At night, the robot watched him _________ (sleep). It knew everything about Mr. Mott.

116. My idea is ___________ (have) a meeting at once.

115. Last night I heard Mike ___________ (cry) in the room.

114. I forgot ___________ (bring) my textbook with me.

113. When makes him ___________ (think) I am a scientist.

112. English is not so easy ___________ (learn) well.