we will go on a picnic if it doesn't rain tomorrow?改为同义句

We will go on a picnic unless it rains tomorrow.
或
We won't go on a picnic if it rains tomorrow.这句话是什么意思？明天如果不下雨，我们就去野餐。I like swimming in the river,My sister likes swimming in the river,too.该为同义句。Both my sister and I like swimming in the river. Not only I, but also my sister likes swimming in the river. My sister and I like swimming in the river.