They often help each other.（改为否定句)

I often help each other .怎样改为同意句? Aften shool they often help each other. They nodded and shook hands with each other（改为否定句） It's good to help each other.改为同义句 You look like each other.怎么改为否定句. Ask each other and discuss it.(改为否定句) They like help each other .help each other 提问 They help each other () they learn from each other They all look like each other.(改为同义句) How do you often help each other? Good friends often help each other when they m_ some trouble 英文单选：They often help ____ other.A:one B:each C:every D:for