my mother bought a microwave oven yesterday 改为被动语态
问题描述：
my mother bought a microwave oven yesterday 改为被动语态
答
A present was bought to my mother by me yesterday . 把……带给某人 bring sth to sb A present was bought for my mother yesteday。
答
A microwave was bought by my mother yesterday.
被动语态的结构是系动词的各种时态加动词的过去分词
答
A microwave oven was bought by my mother yesterday.
答
a microwave oven was bought by my mother yesterday