同学们的性格不同，习惯不同，优缺点也不相同，对每个人来说最有效的学习方法是[ ]

A．学习中要“两耳不闻窗外事”

B．多与同学交流，不懂就问

C．专心听课，少记笔记

D．适合自己特点的学习方法

When an analyst makes an investment recommendation, which of the following statements must be disclosed to clients（）

A. The firm is a market maker in the stock of the recommended company.

B. An employee of the firm holds a directorship with the recommended company.

C. All of these statements must be disclosed to clients.