单项选择 the dictionary is () useful book for studying English. A . a B . an C . the

单项选择 the dictionary is () useful book for studying English. A . a B . an C . the
单项选择
the dictionary is()useful book for studying English.
A . a
B . an
C . the
I want () a map of China.
A.buy
B.is buying
C.to buy