Really do their best是什么意思?

Really do their best是什么意思? to do their best意思 They both didn't do their best. 请问是make their best to do sth还是make their's best to do sth? Do you think that older people really know best? Really, it is the most important. Do you really? 是什么意思? what do holly and maria like about their best friends? that ,do ,they ,their,said,best ,would,they, Do we really have distance是什么意思 How do places get their names?是什么意思 parents hope their children can do their best in class ,so t try my best to do myself是什么意思