106. References will be furnished _____. (A)at cost (B)by installment (C)on approval (D)upon request 。

110. 下列書信內容屬何種函件？"While appreciating the a ttractive design of yo ur high-rise bicycles, we suggest you make some allowance. A 10% reducti on would facilitate the transaction and help introduce your goods to the rap idly growing market here." (A)inquiry (B)offer (C)counter-offer (D)sales 。