降半旗的英文：
to fly/hoist a flag at half-mast (as a sign of mourning)
Flags are to be kept at half-mast .

The flag is flown at half-staff upon the death of him.
他去世之后，降半旗致哀。

All the flags were flying at half-mast,ie in honour of a famous dead person.
所有的旗帜都降半旗致哀.

Flags were at half mast everywhere on the day of the president's funeral.
总统葬礼那天，全国到处降半旗致哀。

Fly in the ointment
一粒老鼠屎坏了一锅汤

Fly on the wheel
狂妄自大的人

all the months fly by.
十二个月匆匆飞逝。

They hoisted the flag.
他们升起了旗。

Concret was raised by a hoist.
混凝土由升降机提升。

crane:To hoist or move with or as if with a crane.

Show the Flag / Fly the Flag
亮相，露面，显示军事力量

strike the flag
降旗表示投降|降旗离职

They striked the flags.
他们降旗投降了。