ad buying system的用法和样例：
- As consumers we must see its good side, but also understand the bad side, using ad buy genuine products is the most important! ! !
- These days, even small companies can buy systems that store many gigabytes of data.
- Buying a house is the best hedge against inflation.
- Don't buy a used car from that rogue.
- I come in answer to your ad for a salesman.