利用

We must make rational and efficient use of foreign capital.

effectively utilize

make full use of; exploit fully; exploit to the full

make use of waste material; turn scrap material to good account

use/exploit natural resources

make use of/exploit every opportunity

utilize/exploit foreign investment; utilize foreign capital; use foreign funds

utilize one's vacation to make social investigations

It is immoral to take advantage of somebody else's mistake.

each using the other for his own interests/ends/gains

be exploited/used (by another person); be a cat's-paw; be taken advantage of

feel used

take advantage of one's position and power; abuse one's power; exploit one's authority (for personal gains)

exploit/use one's friends