Each sentence contains an error in the parentheses. Thanks!!!! 1.The opera, (even though) performed (by) amateurs, (it) (was) excellent. 2.I did not understand (their) predicament (until) John explained (me) all the details of (the mishap). 3.His father mentioned (to me) that Robert (had written) (to him) requesting money (for buying) a new car. 4.I was surprised (to hear) that the store charged (Dr. Brown) an extra amout (when it delivered) (to his office) his new sofa.