大日子的英文：
red-letter-day
adj. 红色的；褐红色的；深红的；布满血丝的；支持左翼政治观点的；社会党的
n. 赤字；亏空
Red got his nickname for his red hair.
“红毛”的绰号源于他的红头发。
The sun will swell into a red giant.
太阳将膨胀为一颗红巨星。
red lake C pigment
色淀Ｃ颜料红
n. 字母；信；字面意义；证书，许可证；文学
v. 用字母标明，写字母于；写印刷体字母；赢得校名缩写字母标志
in letter and in spirit
在字面意义和精神实质上|无论形式和实际
The letter was a forgery.
这封信是伪造的。
Post the letter through the slit in the letter box.
把这封信从信箱的投信口投进去。
n. 一天；白昼，白天；工作日；时代，时期
Things go on day by day.
事情逐日进行着。
Day by day the situation is improving.
情况在一天天地好转。
Like this, day after day.
就这样，日复一日。