Cristiano Ronaldo, CFA, is a mutual fund portfolio manager at Bengal International Investment. The fund is focused on the global financial services sector. According to the Standards of Professional Conduct relating to Duties to Employers, which of the following statements is most accurate If Ronaldo leaves Bengal Intemational Investment to join Jason Investment Management Corporation, a competitor of Bengal, all of his research records:（）

A. can be recreated at Jason from his memory, provided no records are taken from Bengal.

B. are the property of Bengal and cannot be taken without Bengal's permission.

C. may be taken to Jason,provided he is the sole author of the research.

安全卡瓦在井口使用时，要防止（）等落井。

A.钻诞

B.铰链

C.丝杠销及手工具

D.卡瓦