筋疲力尽

人们以为淡水是取之不尽的，因为我们可以从雨水、河水和井水中得到淡水。

你同意世界资源会很快用光的说法吗？

used up

used

STANDS for golf-clubs, used on the course

be used to

STROBOSCOPE used for measuring angular speed

rotary type drive, pneumatically drive used in boreholes

building used in operation

RESONATORS used in transit-time tubes