【多选题】下列哪项是工程数据采用数据库管理的方式处理时对数据库管理系统的要求
【简答题】X染色体灭活是一个独特的发育调控机制,该机制关闭整个染色体上所有基因的表达,人类中灭活包括1.5亿碱基对和几个基因,在正常的女性中随机灭活两个X染色体中的一个,一条X染色体的失活导致X连锁基因的表达,就像在正常男性体内单一X染色体上的基因一样表达。虽然这一失活的机制尚不清楚,但有人猜测启动这一机制的是染色体上的一个特异域——X染色体失活中心,然后再将其扩展到染色体的其他区域。 虽然在失活的X染色体...
【单选题】在打奶泡时,蒸汽棒的蒸汽头保持在牛奶液面下( )厘米的位置。
【单选题】According to Richard,what was the concept of health before the 1940s?
A.
Mechanical operation of the body.
B.
Absence of disease or illness.
C.
Physical, mental and social well-being.
D.
Clean water, improved sanitation and housing.
【单选题】What publications should a GMDSS Operator consult regarding the proper set-up and operation of vessel equipment ________.
B.
The manufacturers instruction manuals
C.
Part 90 of the FCC Rules and Regulations
D.
Code of Federal Regulations,Title 47,Part 80,Subpart W
【单选题】What is the major function of paragraph 1?
A.
To arouse the reader's happiness.
B.
To introduce the theme of the whole passage.
C.
To summarize the whole passage.
D.
To sate the complete bad uses of TV.