【原创】He knew the problem was serious and promised to look into it _____ he reached office.
. The missing boys were last seen _______ near the river.
. The patient was warned _______ oily food after the operation.
. I regret _______ you that we are unable to offer you employment.
. You had better get a doctor _______ your bad tooth.
. The matter had better _______ as it is.