The last of the residential buildings at CityCenter officially opened Thursday, with the two leaning Veer Towers welcoming its first residents and opening model units. The two 37-floor towers include a mix of studios, one-, two- and three-bedroom units and penthouses. The units range in size from 500 to 3,300 square feet and cost between $348,000 and about $2 million, depending on the size and features of the unit.