①注视物镜,用手调节粗准焦螺旋,使镜筒下降
②看到物体图像后,调节细准焦螺旋,直到物像清晰
③将所观察的玻片标本放在载物台上
④左眼注视目镜,并用手调节粗准焦螺旋,缓慢地提升镜筒
— I prefer western food. It's delicious and good for us.
— ? But western food is said to be high in sugar and fat.
听觉产生的过程中,接受声波刺激的部位是( )