Use the words in brackets to complete these sentences. You may need to change or add some words.

17           If we had a video conferencing system, our travel costs  _____________________. (reduce)

18           We______________________ problems. (have / more / more)

19           Could we ______________________ e-commerce? (find out)

20           The number of sales ______________________. (decrease)

21           Our website uses a system to code messages, ______________________ encryption. (call)

22           ______________________ how to archive old messages? (could / tell / me)

23           The number of site visitors ______________________. (go up)