When we are doing the line for for 2D sketch in drawing, After clicking the line command and choose the desire plan to sketch. It will prompt us to click again at the line command to do another line. Below is the example for the line command. The diagram shows that there is two different line, the top and bottom. For the bottom one when we use the usual command, we can make continuous single line until we cancel it by clicking esc on the keyboard. The top one which is the it will prompt us to click back the line command if we want to continue to make the line continous. This one we can go to Option > System Option > General > uncheck the Use Single Command Per Pick.