对文件的保护与保密可以采用存取权限控制。可设置的完整的基本权限是( )。A．只读、

下列图例中，通常用于表示水库的是

A、A

B、B

C、C

D、D

劳动者的素质不包括（）

A．体能素质

B．智能素质

C．非智力素质

D．以上都不是

请利用图所示的实验装置，设计一个实验，测动滑轮的机械效率，请写出主要实验步骤、画出实验数据记录表。（5分）

2月5日，张三从美林公司购买了一批健身器材，约定分期付款，款付清之前，所有权由美林公司保留。合同对交付地点未作约定，3月1日，美林公司办理了托运手续，3月2日，该运动器材在运输过程中因发生不可抗力完全毁损，对此下列说法正确的是哪项( )

A．该器材毁损、灭失的风险应由张三承担
B．该器材毁损、灭失的风险应由美林公司承担
C．张三可以向承运人请求损害赔偿，承运人应赔偿
D．美林公司可以向承运人请求损害赔偿，承运人应赔偿

This book is written expressly for students in an attempt to present the material that is most useful and interesting to them. Previous courses in chemistry are not necessary for the understanding of the material, although those students who have had high school chemistry will find that a review of the inorganic section will better enable them to master the organic and biochemistry sections that follow.

The author has felt that in the past there was an improper selection of material from inorganic, organic, and biochemistry in the majority of the textbooks of chemistry for nurse. The tendency has been to develop the inorganic chemistry to such an extent that organic and biochemistry is covered too briefly. The recent advances in biochemistry and their widespread application to the practice of medicine and nursing have considerably altered the situation. Not only is biochemistry more closely allied to the practical chemistry of medicine and nursing but also it is of more interest to the student. In the author’s experience the response to biochemistry has always been more favorable than to the other sections. Within the brief period allotted to chemistry, therefore, the sections on inorganic, organic, and biochemistry should be so arranged that a good share of the time is spent in the study of biochemistry. This book presents mainly those fundamentals of inorganic and organic chemistry that are necessary for the understanding of the section on biochemistry.

The fundamental points suggested in the Curriculum Guide are included in the book, with some additions in the biochemistry section. The author feels that a study of urine, vitamins, nutrition, and hormones is so obviously a part of biochemistry that at least the fundamentals should be included in this course.

The book has been planned in such a way that it may be adapted to various courses in chemistry. The material suggested by the Curriculum Guide is covered in the first nineteen chapters and may be used in accelerated courses or where minimum time is allotted to chemistry. When the time allotted to the course is sixty to ninety hours, the entire contents of the book may be used to advantage. While the book has been written especially to fit the needs of Schools of Nursing, it could readily be applied in instances where students are required to take but one course in chemistry.

The apathetic attitude of nonprofessional students toward a course in inorganic chemistry may well be overcome by the proper presentation of material selected from inorganic, organic, and biochemistry.

The purpose of this book is（）

A. to provide students with helpful and interesting material

B. to preface the Curriculum Guide with a brief account of biochemistry

C. to present inorganic and organic chemistry in details

D. to raise nonprofessional students’ interests in chemistry