It is important for solving the problem of vibration and wave to determine correctly initial phrase and phrase at any moment.

正确确定初相和任意时刻的相位，对于解决振动和波动问题至关重要。

youdao

Milton corrects -- it's as if he's correcting the sense of monotony with which he had begun the poem, and he corrects that sense of monotony by rewriting that initial phrase.

弥尔顿纠正道-正如他纠正那种单调的枯燥感,他用诗歌的开头句进行了纠正，他还通过重写开头句来纠正那种枯燥感。

耶鲁公开课 - 弥尔顿课程节选