1 The blues has been _____part of African-American culture since then, and it is still ______ important part of American culture.
A. a; a B. / ; an C. the ; a D. / ; a
2 I ______their method of making the machine .
A. adopted B. voted C. elected D. commanded
3. China has been working very hard to stop the endangered animals ______ .
A. dying out B. dying away C. dying down D. dying hard
4. In the past 5 years a great deal of money _____ improving the environment of the school.
A. is spent B. has been spent C. was spent D. had been spent
