主动变被动
my brother used to make me do the homework for him
主动变被动
I used to ____ ____ ____ ____ the homework by my brother
参考答案:be made to do
make 在这里是一种使役动词，这类动词有一个特点就是主动是省略to ，但在被动用法时要加上to，类似用法的还有感官动词，顾名思义感官动词就是指与五官有关的动词如see hear 等，see sb do sth sb be seen to do sth
不过感官动词在主动用法是do还可以换为doing，强调正在进行see sb doing sth