1、It can be said with certainty that...可以肯定地説......
2、What calls for special attention is that...需要特別注意的是
3、It's generally recognized that...它普遍認為...
4、But the problem is not so simple. Therefore然而問題並非如此簡單，所以……
5、Nothing is more important than the fact that...沒有什麼比這更重要的是…
