If science's proper object was the real as sensible, then any object of sensible experience would have its own science. Every object does not have its own science, therefore science's proper object is not the real as sensible.
To the major: Science most properly deals with abstracted universality which is separated from any individual existing thing. This is why we can have a science of humanity. If this were not the case, we would need to have a science of individuals; a science of Ryan and a science of Peter. Human knowledge, then, concerns itself with the objects of sense experience, but not as sensible. The human intellect is able to consider the objects of our experiences as instances of kinds, with science being primarily of the kind and not the instance.
This means that science is about the real world, but not in a direct way. Our knowledge needs to be indirect because the real world is a world of particular things, meaning things that are made of matter and form and subject to motion. Our science, though, must be necessary and unchanging. Therefore we need a necessary knowledge of a contingent world. This cannot be had directly, so science cannot be of things as particular sensible objects.