实验开始前，老师要求我们检查锥形瓶是否干燥，并确认瓶口没有裂纹。
Before the experiment began, the teacher asked us to check that the Erlenmeyer flask was dry and that its mouth had no cracks.
Before the experiment began, the teacher asked us to check that the Erlenmeyer flask was dry and that its mouth had no cracks.