make a great deal of difference是什么意思

make a great deal of difference [英]meik ə ɡreit di:l ɔv ˈdifərəns [美]mek e ɡret dil ʌv ˈdɪfərəns 有很大差别,有很大不同 [例句]Yet the mayor can make a great deal of difference to transport ,and has done so。但是市长可以对公共交通做大量改变,并且他也已这么做了。