重点讲解：
1. add up 加；
Add up the figures in this column.
把这一栏的数字合计一下HXoNR=vVW!。
2. thanks to 幸亏；归因于；
Thanks to the angle at which he stood, he could just see the sunset.
由于站的位置视角好，他刚好能看见日落!o4kVMuHRZVWUm&1。
3. in theory 从理论上说；照理说；
In theory, the buyer could ask the seller to have a test carried out.
理论上，买方可以要求卖方进行一次测试x-|L!32BxZ。
4. get down 俯身；跪下；趴下；
She got down on her hands and knees on the floor.
她双手撑地跪在地上Vv;KC6ZQTmmM.Dh=@。