1.

highlight高亮,  circle圈,  underline下划线,  annotate注释. 

2.句型：

I have highlighted the important information in red.

我已经用红色标出了重要信息。

Spelling mistakes are circled in red.

拼写错误用红色圈出来。

Some readers would underline the page as they read.

有些读者在阅读时会在页面上划下划线。

Please annotate while you are reading.

阅读时请加注释。