Ahmed is a cotton grower. He supplies his cotton to textile manufacturers. In June 2010 he entered into a contract with Shah Textile Mills Limited (‘STML’) for sale and supply of cotton. He received Rs. 100,000·00 as advance payment from STML. In August 2010 his cotton crop was destroyed by the severe floods in Pakistan.Required:In relation to the law of contract, advise Ahmed and STML on the impact of this event on their contract. (10 marks)

引信按受外力分为压发引信和电引信。