单项选择题
A．It keeps blood vessels from being blocked. B．It speeds up their recovery after surgery. C．It increases the blood flow to the heart. D．It adjusts their blood pressure.
A．They wanted to follow his example. B．They fully supported his undertaking. C．They were puzzled by his decision. D．They were afraid he wasn’t fully prepared.
A．called B．addressed C．informed D．surveyed