(a) On Monday 1 July 2008, an advertisement together with application forms for shares in a public company called Country and Town Petroleum Ltd appeared in a daily newspaper The Echo. The shares cost US$10 each. Sly saw the advertisement and on the same day sent an application for shares in Country and Town Petroleum Ltd, together with a cheque of US$50,000. This application was received by the company on the next day. It was processed on Thursday 3 July 2008 and the share certifi cate was posted to Sly that morning. Meanwhile, Sly had changed his mind. Early morning on Thursday 3 July 2008, he sent a letter to the company indicating that he no longer wanted to purchase the shares. Later that day, it emerged that Country and Town Petroleum Ltd had found new, vast reserves of oil near Chinhoyi and overnight, their shares on the Stock Exchange trebled in value. Early that evening Mr Chancer the company secretary telephoned Sly telling him that the company was not accepting his application to purchase shares and asking him to return the share certifi cate when it arrived by post. Having heard of the oil discovery, Sly did not want to return the shares and was now very keen to be a shareholder.Required:In relation to the law of contract, advise Sly of his legal position in relation to the company in light of the above facts. (5 marks)

按建筑物的形状和作用分为（）、垛、护岸、顺坝、导流坝、潜坝、锁坝等。

A.土坝

B.石坝

C.丁坝

D.混凝土坝