It is such thin ice that we can't skate ______.应该填on还是on it?

It is such thin ice that we can't skate ______.应该填on还是on it? The ice is so thin that we can't skate on it为什么要加it 一个句子最主要不 The ice is so thin that you can't skate on it the ice is so thin that wen can't skate on it 同义句 The ice is too thin.You can't skate on it.改为同义句 The ice is so heavy that we can skate on it 改为同义句 We are excited that we can skate on ______ ice. the ice is too thin ------ A to skate on it B skating on it It‘s to skate on such thin ice 适当形式填空 The ice was so thin that peopie could not skate on it.(改为同义句 为什么不是the ice is too thin to skate on （it)? The ice is very thin.You can't play on it.改为同义句