当然是please  do  sth. 这是一个祈使句,please为虚词,不影响句子结构.而祈使句当然是以动词原形开始. 且：Please  do  sth. =  Do  sth, please. 如：Please  sit  down. =  Sit  down, please. 请坐下.
语法中please to do sth还是please doing sth 还是please do sth?