Don't have the machine ____all the time .It will go wrong.为什么填running(要加ing)

问题描述:

Don't have the machine ____all the time .It will go wrong.
为什么填running(要加ing)

all the time 一直的意思 running表示进行式 have 是使役动词加doing表示使某物保持进行的状态