根据以下资料，回答51-55题： Directions : The following is a list of terms about meeting. After reading it, you are required to find the items quivalent to (与…相同的． those given in Chinese in the table below. Then you should put the corresponding letters in brackets on the Answer Sheet, numbered 51 to 55. A—to hold a meeting E—final sitting B—working party F—formal sitting C—meeting in camera G—plenary meeting D—opening sitting H—study group I—budget committee M—board of directors J—drafting committee N—executive council K—committee of experts O—standing body L—advisory committee P—committee Examples：(M．董事会 (H．学习研讨会 （　　）秘密会议 （　　）执行委员会