Although their new factory building is still under          construction，we have already placed        order for 200 pairs of shoes.

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

Although their new factory building is still under          construction，we have already placed        order for 200 pairs of shoes．

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