1．构成：shall / will have + 过去分词
►. They will have been here for 5 years next Friday.
►. By the end of next term, the students will have finished the book.
1．构成：would / should have + 过去分词
►. He said that they would have arrived by seven o"clock.
1．构成：shall / will have been + 现在分词
►. We shall have been staying here for four weeks when Tom arrives.
►. It will have been raining for a week if it does not stop tomorrow.
1. Simple photographic lenses can"t ________ sharp, undistorted images over a wide field.
A. to form B. are formed C. forming D. form
2. Of all the factors affecting agricultural yields, weather is the one ________ the most.
A. it influences farmers B. that influences farmers
C. farmers that it influences D. why farmers influence it
3. By tracking the eye of a hurricane, forecasters can determine the speed at which ________.
A. is a storm moving B. a storm is moving
C. is moving a storm D. a moving storm
4. During the flood of 1927, the Red Cross, ________ out of emergency headquarters in Mississippi, set up temporary shelters for the homeless.
A. operates B. is operating C. has operated D. operating
5. Of all the economically important plants, palms have been ________.
A. the least studied B. study the least
C. study less and less D. to study the less
6. During an eclipse of the sun, ________ in the shadow of the Moon.
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
C. living are a group of elements
D. are normal elements of group life
1. D 2. B 3. B 4. D 5. A
6. A 7. B 8. C 9. A 10. D