on the ground that

因为，鉴于

on one's guard, on one's head, on one's honor, on one's honour, on one's own, on one's way to..., on order that, on principle, on purpose, on relief, on sale, on schedule, on second thoughts, on the alert, on the analogy of, on the average, on the basis of, on the contrary, on the eve of..., on the first try, on the grounds of, on the impulse (of...), on the increase, on the lips of, on the nail, on the other hand, on the part of, on the point of, on the principle of, on the quiet, on the road, on the run, on the side, on the sly, on the spot, on the stroke, on the table, on the trail, on the trail of sb., on the turn,