for和since在现在完成时的不同,那个a day ,year这些为何是since,last year怎么也是,复数d

for和since在现在完成时的不同,那个a day ,year这些为何是since,last year怎么也是,复数d since last year 可以 用现在完成时吧? Jim has lived here ( ) last year .A./ B.for C.before D.since since 和for在现在完成时的使用 I ____him since last year last year怎样用since回答 We have___________much money for the project since last year 现在完成时走since和for怎么用 My brother has worked as a waiter since last year. he has been a soldier since last year同义句 在现在完成时中for,since的区别. 现在完成时中since和for的区别