ad astra per aspera的用法和样例：
- People who work in the space business like to keep the motto per aspera ad astra close to their hearts.It means “through hardship to the stars”.It was never intended to be a bureaucrats' charter.
- I come in answer to your ad for a salesman.
- We were told to help ourselves to the food ad lib.
- Problems were solved on an ad hoc basis.