2、it pays to 是值得的；it pays to help others 帮助别人是值得的。
3、be based on 以...为基础；the progress of thee society is based on harmony 社会进步是以和谐为基础的。
3、adj + as + subject（主词）+ be， s + v~~~ （虽然……）
例句：rich as our country is,the qualities of our living are by nomeans satisfactory.
{by no means = in no way = on no account 一点也不}
虽然我们的国家富有，我们的生活品质绝对令人不满意。
4、by +ving， ~~ can ~~ （借着……，……能够……）
例句：by taking exercise， we can always stay healthy.
借着做运动，我们能够始终保持健康。