A student asked me about the two uses of the word "by" in these sentences:
Korea was the only country that managed to reduce its waste output by the year 2000. Korea cut its waste output by 12 million tonnes between 1990 and 2000.
1. Can you explain how "by" is used in the two cases above?
2. What is the difference between "by the year 2000" and "in the year 2000"?