7点45用英语两种表达:forty five past seven、seven forty-five。
past:
adj.过去的;昔日的;刚过去的;刚结束的;从前的;以往的;

(图片来自网络侵删)
n.过去;昔日;过去的事情;
prep.晚于;在…之后;在另一边;到另一侧;
adv.从一侧到另一侧;经过;
复数: pasts
相关介绍He has matured a great deal over the past year.
经过过去这一年,他成熟了许多。
In some sports you're past it by the age of 25.
在某些运动中,人过25岁就难有作为了。
The time is now half past ten.
现在是十点半。
I haven't seen much of her in the past few weeks.
近几周来我很少见到她。