I think the talk given by the old scientist is ______ worth ______.
Lei Feng always _______ the interests of the people _______ everything else, which has been praised highly by people all over the country .
There are things people accept less , ____ you defend them.
In no country ______ Britain , as is often said , ______ experience four seasons in a day .
--- The accident might not have happened , had we been more careful . --- But we _______.
The more you learn , _______.