Method 1: enter m first, then select r, then format-Chinese layout-circled characters, and pay attention to select "Increase the number of circles". Method 2: Make an empty circle, make an m, select two characters, and adjust the character spacing. You can find the empty circle of R in the insert-symbol: because the circled m is not a common symbol, you don't need to choose R. Others, such as copyright symbol (circled c) and registered trademark (circled r), you can choose from the symbols, or you can directly put parentheses and write letters in it, and the automatic modification function of WORD will be replaced by the corresponding characters.