it"s hightly reliable in ( operate ) _____ .

问题描述:

it"s hightly reliable in ( operate ) _____ .
We have never had any problem with our car in the past three years ; 这是前半句,适当形式填空
in 后面可以跟些什么词啊,adj,还有?

in operation:操作中,运转中
大概意思是我门的车在过去3年没有任何故障,运作自如!