题组内容描述:
5. The image shows a respirometer which is designed to measure the rate of use of oxygen of geminating black eye bean seeds. whole apparatus is submerged in an electronic water bath set at$25^{\circ}C$.

For each trial, first the clips are opened for 5 minutes. Then the clips are closed and the syringe used to make the red coloured water in the manometer level on both sides (as shown in the diagram). The reading on the syringe is recorded. The beans are left to respire for 15 minutes and then the syringe is used to reset the level in the u-tube. The volume of oxygen used in respiration is estimated by measuring the volume of gas in the syringe needed to reset the level to the start point.