We are sure that ________ to do this face to face, he would express himself more easily.
本题考查虚拟语气的用法。that从句中，含有虚拟语气（对将来的虚拟）即： If he were to try to do this face to face，if从句中如果含had,were,should时，可将它们提前，省略if。
【参考译文】我们肯定如果他试着面对面地来做这件事的话，他更容易表达他自己的意思。