小精灵926
You can be assured that ...You can set your mind at rest about ...You could rely on it that ...You can be at ease about sth.
SSpapergirl
rest assured 放心don't worry 别担心set one's heart at rest 安心rely upon it 放心take it easy 放轻松,别紧张想到的就这些,都是比较口语化的,根据不同场合来用吧~基本都可以互用的~