last year l________135cn.this year l_________145cm.

last year l________135cn.this year l_________145cm. last year at this There ------pollutions this year than last year. There's_____（little)rain this year than last year. This year our school is___than it was last year He _________ harder this year than last year. There will be___ pollution this year than last year This year they have produced ____rice ___they did last year. 1.They produced ____electricity this year than last year. we have ___(little)rainfall this year than last year I study ________hard this year than last year this year than last year一般用什么时态?