Honestly? In a properly instructed science class, any gaps in evidence or logic should already be being taught. Science by nature should be self-critical and constantly skeptical, constantly questioning.
If someone taking science doesn't understand that "we're not too sure about anything, really," then the teacher isn't doing their job (or they're pushing an agenda).
In current high school biology textbooks, how much print is devoted to problems with the theory of evolution? Last one I looked at, a couple of years ago, I don't remember seeing ANY criticism of the theory as it's promoted by evolutionist scientists.