I encountered the following problem in Complex Geometry-an introduction of Dianel Huybrechts:
Show that any submanifold of a complex torus has nonnegative Kodaira dimension.
Since $\operatorname{kod}(T^n)=0$, I think it's sufficient to show that if $f: Y\to X$ is an embedding, then $f^*:Q(X)\to Q(Y)$ is a field embedding, where $Q(X)$ is the canonical ring of $X$. I wonder how to prove it. Thanks in advance.