we are playing (play)football now
因为后面有now
所以用现在进行时what___you____(do)?what are you_doing _(do)?What did you do?What will you do?都可以，因为没有语境what____he____(mend)?what_is _he mending (mend)?What did he mend?What will he mend?he____(mend)a carhe is mending (mend)a carHe will mend a car He has mended a car