I have written a paragraph of text and one line is protruding out into the right margin. I am completely baffled, can anyone help?
My text is thus
"... cohomology of the base manifold. These invariants describe the obstruction to the presence of global sections, which we may interpret as a measure of the twisting of a bundle.
Today there are three main expositions of characteristic classes: Chern-Weil theory; the approach of Grothendieck; and the study of universal bundles. Each exposition has its merits and its drawbacks, and we shall not have time to present all three. We will focus initially on the Chern-Weil approach as presented in Madsen \& Tornehave \cite{Madsen} in which characteristic classes are derived by taking invariant polynomials in the curvature form, a construction well studied in differential geometry. This approach is preferred as it leads to simple proofs of the important naturality and Whitney-sum properties. We will then discuss briefly the approach of Grothendieck as presented in Bott \& Tu \cite{Bott} which deserves attention simply for its elegance. Here a class is constructed for a rank 2, oriented vector bundle, living in the cohomology of the base manifold, which is seen to pull back its information from the fibre above, counting the number of obstructions to the presence of a global section. Then, using the Leray-Hirsch theorem and some clever algebra as well as a result from cohomology, characteristic classes are derived from this for general complex vector bundles. This approach allows us to present a clear computation.
Neither of these first two expositions really address the important question of {\textit{why}} such characteristic classes..."
And here's how it is coming out!

Any ideas?
Thanks, Adam.


\begin{sloppypar}...\end{sloppypar}, or define a specific hyphenation pattern forGrothendieckusing\hyphenation{Gro-then-dieck}or use it inlineGro\-then\-dieck.Gro\-then\-dieck.\hyphenation{Grothen-dieck}; then it will be available everywhere in your document, not just in this one place.