单项选择题
According to the selection, the muscular sense is responsible for()
A．the efficiency of our muscles B．the normal breathing function C．directing our muscles intelligently D．the work of only our involuntary muscles
单项选择题 Intelligent use of the muscles means that()
单项选择题 Under a microscope , muscle cells appear to be ()
单项选择题 According to the selection more than half of a person's body is composed of()
