细胞生长时，细胞壁表现一定的（）
A、可逆性
B、可塑性
C、弹性
D、刚性
参考答案：C
Mike _____ his computer and checked his e-mail. [ ]
A. turned on
B. turned off
C. turned up
D. turned down
颈椎活动正常范围是
A．前屈、后伸各60°～80°；左右旋转各60°～80°；左右侧屈各45°
B．前屈、后伸各35°～45°；左右旋转各60°～80°；左右侧屈各45°
C．前屈、后伸各35°～45°；左右旋转各35°～45°；左右侧屈各45°
D．前屈、后伸各35°～45°；左右旋转各60°～80°；左右侧屈各80°
E．前屈、后伸各35°～45°；左右旋转各60°～80°；左右侧屈各80°
