crossover experiments
... that crossover experiments are used to study the mechanisms of chemical reactions?
... that <b id="mwDhs"><a href="./Crossover_experiment_(chemistry)" id="mwDhw" rel="mw:WikiLink" title="Crossover experiment (chemistry)">crossover experiments</a></b> are used to study the mechanisms of <a href="./Chemical_reaction" id="mwDh0" rel="mw:WikiLink" title="Chemical reaction">chemical reactions</a>?