问题详情

Which of the following is CORRECT about the decline of birds in Europe？

A．The quantity of birds in Europe dropped by about 500 million.

B．90% of the drop in Europe occurred in the last decade.

C．Ms. Thatcher was the first one to notice the decline.

D．The most common species are the most vulnerable.

请帮忙给出正确答案和分析，谢谢！