reduce/ rɪ'djuːs /

1.vt.[+spending] [ numbers] [ risk etc] 
减少

to reduce sb to sth
使某人沦落到某种状态
to reduce sth to sth
使某事陷入某种状态
to reduce sth by/to
将某物减少…/将某物减少到…
to reduce sb to tears
使某人伤心流泪
to reduce sb to silence
使某人沉默
"reduce speed now"
 [汽车] “现在减速”