英语语法分析

Philipp Hildebrand, president of Switzerland’s central bank, expressed similar doubts.

瑞士央行总裁Philipp Hildebrand也表示出同样的疑虑。

The pitch got lower, Hildebrand believes, because there are more whales now than several decades ago.

希尔·德兰认为，音调变低是因为现在蓝鲸数量比几十年前多。

John Hildebrand: the animals had decreased the pitch of their songs by about 30% from the 1960s to today.

约翰·希尔·德布兰：从上世纪60年代至今，这种动物已经将他们歌声的音高降低了大约30%。