1. to have(many) irons in the fire: to have a lot of activities going on at
Don't bother him because he has many irons in the fire.
Some people even like to have many irons in the fire.
2. to talk over (one's) head(s): to use large or big words so that audience
not understand exact
Dr. Lee's lecture was so specialized that he almost talked over our
In order to show his profound knowledge he talks over my head.
3. to put (something) back into (in) its cage: to put something under
We are trying to put inflation back into its cage and our economy is on
Diplomats and politicians need to put aggression and hostility back into
4. to keep (one's) fingers crossed: to hope something good will happen
"I wish you best (good) luck!"或 "Good (best) luck to you!")
He keeps his fingers crossed hoping his father will send him more
Many people have been keeping their fingers crossed that we can live in
peaceful world. (许多人都在祈求好运，盼能在和平的世界里生活。)
5. to stretch (one's) legs: to relax or to take a short break
Let's take ten minutes to stretch our legs. （让我们先休息十分钟。）
May I take a break so that I can stretch my legs？ (我可以休息一会儿伸伸腿吗？)
During the a long flight from the US to Taiwan, I normally stretch my legs
two hours. (在从美国到台湾的长途飞行中，我通常每两个小时起身走走。)
6. to read between the lines：to interpret the hidden meaning or a
message; to discern the true fact
As you look at this poem, be sure to read between the lines.
After he re-read the love letter between the lines, he realized that he
dumped by his sweetheart. (重读情书之后，他终于明白他已经被情人抛弃了。)