( )16.While he was investigating ways t improve the telescope Newton made _______discovery which completely changed ____ man’s understanding of color.

　　A. a ,/ B. a ,the C. /, the D. the ,a

　　( )17.It is ___world of wonders, _____world where anything can happen.

　　A. a. the B. a, a C. the, a D. /,/

　　( )18.The Wilsons live in ______A-shaped house near the coast . It is _______17th century cottage.

　　A. the, / B. an, the C. /, the D. an ,a

　　( )19.Tom owns ______larger collection of ______books than any other student in our class.

　　A. the ,/ B. a,/ C. a ,the D. /, the

　　( )20.For a long time they walked without saying ___word .Jim was the first t break _____silence.

　　A. the, a B. a ,the C. a ,/ D. the,/

　　( )21.There was ____time _____I hated t go to school.

　　A. a ,that B. a ,when C. the ,that D. the ,when

　　( )22.When you finish reading the book ,you will have ______better understanding of ______life.,

　　A. a, the B. the .a C. /,the D.a,/

　　( )23.I earn 10dollars ____hours as ____supermarket cashier on Saturday.

　　A. a, an B. the ,a C. an ,a D . an ,the

　　( )24The sign reads “in ease of___fire ,break the glass and push _____red button”

　　A. /,a B. /,the C. the ,the D. a ,a

　　( )25.I don’t like talking on ______telephone ; I prefer writing ____letter.

　　A. a, the B. the./ C. the ,the D. A ,/

　　( )26.Jumping out of ____airplane at ten thousand feet is quite _____exciting experience.

　　A. /, the B. /, an C. an. an D. the, the

　　( )27.One way to understand thousands of new words in gain _____good knowledge of basic word formation.

　　A. / B the C. a D. one

　　( )28.The cakes are delicious . He’d like have ______third one because _____second one is rather too small.

　　A. a, a B. the .the C. a ,the D. the ,a

　　( )29.A bullet hit the solider and he was wounded in ____leg.

　　A. a B .one C. the D. his

　　( )30.The warmth of _____sweater will of course be determined by the sort of ___wool used.

　　A. the, the B. the ,/ C. /, the D. /,/