Which of the following actions are recommended when releasing fluid from the pipette tip into a container? 在将液体从移液器尖端释放到容器时，推荐以下哪些操作？多项选择题

a. Push the top button down to the first stop only只需按下最上面的按钮到第一站

b. Hold the pipette on a slight angle将移液管稍微倾斜

c. Hold the pipette completely vertically将移液管完全垂直握持

d. Push the tip release button按下弹头释放按钮

e. Push the top button down to the second stop按下最上面的按钮到第二站