He went to his office and continued__________(work)hard on that model plane

问题描述:

He went to his office and continued__________(work)hard on that model plane

之前在做现在还是在做 用continue doing sth
之前没在做现在还是在做 用continue to do
这里前面有说回到办公室 所以他离开做其他事 再回来继续做sth 所以要用to work

to work

working
continue doing sth 继续做某事