92. We fail to understand why you have not settled your account of $1,520, wh ich is now two months _____. (A)overwork (B)overtime (C)oversight (D)overd ue 。

54. We appreciate your patience and please _____ that we will do everything i n our power to _____ that this type of error does not occur in the future. (A)assure....ensure (B)be assured....be ensured (C)assure.....be ensured (D)be a ssured....ensure 。