1.____ the text a second time,the meaning will become clearer to you.
A.Read B.Reading C.When you read D.If reading
2.Ocean currents affect the climates of the lands ____ they flow.
A.on which B.near which C.out of which D.from which
3.At the beginning of class,the noise of desks ____ could be heard outside the classroom.
A.opened and closed B.to be opened and closed
C.being opened and closed D.to open and close