It’s often less expensive to buy goods in ________ quantity, but you’d better examine ________ quality before buying them．

1. A.
   /; the
2. B.
   the;/
3. C.
   a; the
4. D.
   the; the

It’s often less expensive to buy goods in        quantity, but you’d better examine     quality before buying them.

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