Question

1．众所周知纸是由木头制成的．
It's well known that paper is made from wood．

Answer 1

分析 It's well known that paper is made from wood．

解答 答案：It's well known that paper is made from wood．这里是一个陈述句，说的是客观事实，用一般现在时，表示…是众所周知的用句型It's well known that，it作为形式主语，真正主语是that从句，纸是由木头制成的，看不出原材料，故用be made from，木头wood 纸paper不可数，故答案是It's well known that paper is made from wood．

点评 It+be+过去分词+主语从句，用it作为形式主语，真正主语是that从句，这类过去分词有：announced，believed，expected，hoped，decided，reported，said，shown等，如：
It is reported that 16 people were killed in the earthquake．