Ax, a Swedish manufacturer, contacted Bo, a German manufacturer, to enquire about Bo making special screws of a particularly high quality.Bo provided by return a list of prices and delivery periods.Ax then ordered 3,000 screws and also 3,000 specialised nuts and bolts, not mentioned before.Bo requested payment in advance or a letter of credit. Ax, in turn, asked for a pro-forma invoice.When Bo sent the invoice it listed screws of a lower quality than the original specification with their respective prices.Ax objected immediately and demanded delivery of the articles in the ‘ordered’ quality. Bo agreed to delivery of higherquality articles but insisted on a higher price than on the invoice. Ax insisted on delivery of the higher-quality items but for the price listed in the invoice.Required:Advise the parties whether or not they have entered into a binding contractual agreement on the basis of the UN Convention on Contracts for the International Sale of Goods. (10 marks)

方药配伍中寓“清金制木”之义的是（）。

A.桑菊饮

B.泻白散

C.凉膈散

D.羚角钩藤汤

E.镇肝熄风汤