单项选择题 The main purpose of the Customs supervision and control is to （） China's economic, trade, scientifrc, technological and cultural exchanges with other countries.

单项选择题 Quality of the present shipment is equal to （） of last consignment.

单项选择题 According to the Regulations on Import and Export Tariff of the People's Republic of China, the duty-paying value of an export item should be its normal （） price with the export duties deducted and examined, approved by the Customs.