16. Helen is______ American girl and she is new in______town.
A. a, / B. an, / C. a, a D. an, a
17. The young man went to Duyun for work______a sunny morning.
A. in B. at C. on D. of
18.In our school library there ______ many books on science and the number of them______ getting larger.
A. is; are B. are;is C. has; is D. have; are
