Language Point 11

... when I was offered an opportunity to study English through an online course. (Para.5)
Meaning: ... when I was given a chance to learn English by taking a computer course.
opportunity: n. a good chance, a favorable moment
With the help of his teacher, he got an opportunity to learn English in Britain. 在老师的帮助下，他得到了机会去英国学习英语。
The month of May offers a wonderful opportunity to go traveling. 五月份是旅游的好时机。