VOA慢速英语:Using Lasers to Treat Kidney and Liver Tumors

cut down on减少

例句：Are you trying to cut down on cigarettes?
      你是要戒烟吗？

2.They are given a drug to keep them from moving during the procedure.

keep from阻止; 免于

例句：I don't want to keep you from your work.
      我不想耽误你的工作。

      Urgent business kept me from attending the meeting.
      因有急事我不能去参加会议。

3.When the tumor is heated to the point of destruction, the laser is turned off.

turn off(把…)关掉

例句：The tap won't turn off and there is water all over the floor.
      水龙头关不上, 满地都是水。

      He turned off the water.
      他关上了水龙头。

4.The research found that large parts of Eurasia, Africa and Australia are also at risk.

at risk有危险

例句：The disease is spreading, and all children under five are at risk.
      这疾病在蔓延, 五岁以下的小孩都有危险。