A. the Earth lies                       B. the Earth when lying

C. that the Earth lies                    D. the lying Earth

7. The photo periodic response of algae actually depends on the duration of darkness, ________.

A. the light is not on                   B. and not on light

C. but is not on the light                D. is not on light

8. The wallflower ________ because its weak stems often grow on walls and along strong cliffs for support.

A. so called is                        B. so is called

C. is so called                        D. called is so

9. Because of its importance in modern living, ________ in all parts of the world.

A. algebra is studied in schools and colleges

B. studying algebra in schools and colleges

C. and the study of algebra in schools and colleges

D. in schools and colleges are algebra studies

10. Sociologists have long recognized that social tension ________.

A. elements from group living

B. elements of a normal group life liuxuepaper.com