[liǎo jiě]
（知道得清楚） understand; comprehend; acquaintance
understand the laws of development of things
了解事物发展的规律
A good teacher must understand children.
一位优秀的教师必须了解儿童。
If you can use a word correctly and effectively, you comprehend it.
你如果能正确和有效地使用一个字， 你就了解它了。
keep abreast of current development in science and technology at home and abroad
了解国内外科学技术发展情况