若r(t)=e(t)*h(t)，则r(2t)=e(2t)*h(2t)

单项选择题. Although they are identical twins their parents can easily ______ between them. A、identify B、select C、differ D、distinguish

单项选择题Spinal nerves found at the level of L4 to about S4 form the A、A)thoracic plexus. B、B) lumbar plexus. C、C) femoral plexus. D、D) sacral plexus.