Here it says to draw the addict product form from the reaction between borane and a hydroxide ion. So remember, borane is BH3, Hydroxide is OH-1. Oxygen itself has three lone pairs. We can use one of these to connect to the boron atom.
So here goes. Our boron still connected to its three hydrogens, and now it's making a new connection with the hydroxide ion. Oxygen still has its other two lone pairs. When oxygen makes its ideal number of bonds, which is 2, its formal charge is 0.
Boron here is gaining additional electrons and sharing them with the oxygen, so its formal charge becomes -1. This represents the newly created addict product between the reaction of our boring molecule and our hydroxide ion.