This paper is a continuation of our previous work concerning three-dimensional complete manifolds with scalar curvature bounded from below. One of the purposes is to improve a sharp comparison theorem for the bottom spectrum by removing a volume assumption on unit balls. Another purpose is to derive geometric information when the scalar curvature is assumed to be bounded from below by a positive constant. When the Ricci curvature is asymptotically nonnegative, it is shown that such manifolds must be parabolic and that the lower bound of the scalar curvature is explicitly bounded by the volume of unit balls. In particular, in the case that the Ricci curvature is nonnegative, this implies that the volume of the manifold must grow linearly, which answers a question of Gromov for dimension three.