MileStone-3:-Preliminary-Requirements.md

@@ -12,7 +12,7 @@ As Jack, one of the function of our website can provide pre-order service by usi
 
 As Jack, I want to be able to order the coffee what I want quickly in advance, which save my time. 
 
-Tests: 
+**Tests:** 
 
 a.Test with clicking the coffee I need (pass)