Think hard
Worry, worry, worry, worry, worry, worry, worry, worry. It's from experience.
Idiom explanation
Worry and think.
The origin of Idioms
Zou Taofen's experience: "all my attention at this time is focused on the invasion of Suiyuan. What I worry about everyday is this problem."
Idiom usage
As a predicate, adverbial, or bitter thought
Think hard
strange voice or an affected manner - guài shēng guài qì
run out of ammunition and food supplies - dàn jìn liáng jué