My brother is singing_____my sister is dancing

My brother is singing_____my sister is dancing my brother's sister is my(s ). This is my sister a什么that is my brother? My sister Is eighteen and my brother is sixteen My brother is nine and my sister is ( )four My sister is good at singing and dancing.同义句转换是My sister doe my sister's brother is my mother's. My brother is taller than my sister.(保持原意) My sister is shorter than my brother.同义句 .so is my brother,sister and my uncle对吗? My brother is taller than my sister.(保持愿意） This is my sister and this is my brother 能不能写成this is my sis