at the end of,by the end of,in the end of,to the end用法区别

at the end of,by the end of,in the end of,to the end用法区别
( )1 We had learnt more than 3,000 englisgh words -------last termA at the end of B by the end of C in the end of D to the end( )2-------the meeting,everyone stood up to give the applauseA At the end of B By the end of C In the end of D To the end( )3------,Tom finished the novelA At the end of B By the end of C In the end of D To the end