第1个回答 2013-06-28
These books are usually written for children. ?
第2个回答 2013-06-28
This kind of books is usually written for children.
第3个回答 2013-06-28
Is the book always write for chidren?the+可单意思是某一类。。
第4个回答 2013-06-28
this kind of books are often written for children.
第5个回答 2013-06-28
this kind of book is intended for children