over the last 用什么时态?

over the last 用什么时态? over the last year 要用什么时态 over the last three years什么时态? Tom ___（work） in the library every night over the last 3 months.用什么时态 in the last years用什么时态? over the past few years 用什么时态 years ago和over the years用什么时态 over the following years 应该用什么时态? My friends all (keep in touch with) each other over last Christmas.应该用什么时态 over the year 用于什么时态 over the year和什么时态连用 in the last few years 用什么时态 in the last sixty years用什么时态 since the end of last years用什么时态 后面是in the last two weeks用什么时态 for the last two years用什么时态 后面是in the last two weeks用什么时态 in the last ten years应该用什么时态?