through thick and thin
顽强地
A:I cannot understand why she always helps and supports her brother.
A:我真不明白为什么她总是帮助、供养她的弟弟。
B:Why do you say so?
B:为什么这么说?
A:Because he is often in trouble.
A:因为他总是麻烦不断。
B:She had promised her mother that she would be with him through thick and thin.
B:她答应过自己的母亲,她将和弟弟同甘共苦。
A:Oh, I see.
A:我明白了。