小强上课时突然大汗淋漓、头晕眼花，可能的原因是 (    )

A．没吃早饭，出现低血糖现象

B．天气太热

C．没写完作业，怕老师批评

D．上课想睡觉

(a) IAS 8 Accounting Policies, Changes in Accounting Estimates and Errors contains guidance on the use of accounting policies and accounting estimates.Required:Explain the basis on which the management of an entity must select its accounting policies and distinguish, with an example, between changes in accounting policies and changes in accounting estimates. (5 marks)