【简答题】A sign is another kind of language. Here are some of them that you see on the roads. Number One is a sign with the number thirty on it. When drivers see this sign, they must not go at more than thirty...
【简答题】A sign is another kind of language. Here are some of them that you see on the roads. Number one is a sign with the number thirty on it. When drivers see this sign , they must not go at more than thirt...