Without a ______ of a profit, housing developers may simply choose to invest in some other activity.

A．He sold traffic-counting system to local governments.
B．He dropped out of his law course at Harvard University.
C．He founded his own company--Microsoft Software company.
D．He devised an operating system for IBM.

A．He was playing computer games with a few of his friends.
B．He was playing basketball with a few of his friends.
C．He was having a barbecue with a couple of friends.
D．He was watching a game on TV with some friends.