Drawing multistep reaction

Currently I am only able to have one reaction arrow on the marvin sketch page at a time. This means that I cannot draw multistep reaction mechanisms. I can place a normal single headed arrow but every time i place a new structure on the other side there will be a plus sign connecting the reactant and product for that part of the reaction. Is there a way to have two reaction arrows or not have a reaction arrow and be able to manually place the plus signs?

If you like to draw a reaction mechanism (similar to the one on the attached picture), I suggest you using "single arrow" among the arrows (menu Insert>Arrow>Single Arrow ) and adding " +" sign as text (Menu Insert>Text).

Best Regards,

Efi