Is it an idiom that a good dog catches mice?

A good dog catches mice is not an idiom. Liang's idiom begins like this:

Good day: good; Chen: Time; G: Geely. Good times, auspicious days. Later, it was often called a suitable day for marriage.

Beautiful days and scenery.

Good craftsmen: skilled workers; Skilled craftsman: A skilled craftsman. Refers to a skilled craftsman.

A good worker is a diligent worker: a skilled craftsman. Describe the works of excellent artists, who all do their best in the creative process.

The metaphor of Jin Liang and Mei Yu is perfect. It also means that people have excellent moral qualities.

A good bird chooses wood, which is a metaphor for a wise man choosing a teacher.

A mentor who teaches and helps others.

Good medicine is bitter in the mouth. Good medicine is bitter in the mouth. Metaphor sincere advice and sharp criticism. It sounds uncomfortable, but it is good for correcting shortcomings and mistakes.

Good and bad: Setaria viridis and millet are very similar, often mixed in seedlings. There are good people and bad people, mixed together.

Good knowledge and ability always refer to people's preferred ideas and instincts.

Good times and scenery. With "its moments of beauty".

Good workers painstakingly paint the works of excellent artists, and they all spend their time in the creative process. It also means goodwill.

A good bow does not change, which means inheriting the fine traditions and undertakings of parents and grandparents.

Liang Jia hid valuable things from people who can do business and let you know the details. Metaphor means that a truly learned person doesn't show up in front of people.

Tutor Yan Youliang: Good; I dare say it. A good teacher and a friend who can be honest with each other.

A good time, a good time, an auspicious day, is often called a suitable day for marriage. Both are "auspicious days".

Good times and beautiful scenery. With "its moments of beauty".

Good night, good scenery, good night, good scenery. With "Beautiful Night".

Beautiful night, beautiful night and scenery. Also known as Good Night.

Good, bad and not bad: Setaria viridis and millet are very similar and often mixed in seedlings. There are good people and bad people, mixed together, it is difficult to distinguish.

There are different kinds of weeds: green bristlegrass, much like millet, is often mixed in seedlings. Metaphor is good or bad, mixed together. It's hard to tell the difference. The same as "good and bad are intermingled".

Confusion between good and bad: confusion. Miscellaneous: miscellaneous. Good and bad are mixed together. It's hard to tell the good guys from the bad guys. Also known as "the good and the bad are intermingled".