既是我国地势第二、三阶梯的分界线，又是高原与平原的分界线，还是两省分界线的山脉是[ ]

A．太行山

B．大兴安岭

C．巫山

D．雪峰山

Which of the following is the simplest way for a company to increase its reported operating cash flow（）

A. Record sales on a bill-and-hold basis.

B. Slow down the rate of payment to suppliers.

C. use a third party financial institution to pay suppliers.