水库正常运转以后，因为在冬季和2008年春天早期的时候向下游放水，水库水位一直在下降。而汶川地震发生的时候，水库正处在一个低的水位上。

Following normal operation, the reservoir's level dropped as water was released downstream during the winter and early spring 2008 and was at a low level when the Wenchuan earthquake occurred.

youdao

不久以后，在1962年雷切尔·卡森所著、名为《沉默的春天》一书问世了。

Then, in 1962, came a book called Silent Spring by Rachel Carson.

youdao