gwd13-11，再请教

A South American bird that forages for winged termites and other small insects while swinging upside down from the foliage of tall trees, the graveteiro belongs to the ovenbird family, a group of New World tropical birds that includes more than 230 species and that are represented in virtually every kind of habitat.

1. graveteiro belongs to the ovenbird family, a group of New World tropical birds that includes more than 230 species and that are
           
2. graveteiro belongs to the ovenbird family, a group of New World tropical birds that includes more than 230 species and is
           
3. graveteiro belongs to the ovenbird family, a group of New World tropical birds that include more than 230 species and is
           
4. graveteiro, which belongs to the ovenbird family, a group of New World tropical birds that includes more than 230 species and that are
           
5. graveteiro, which belongs to the ovenbird family, a group of New World tropical birds that includes more than 230 species and is

答案是b 根据平行原则得来的

 graveteiro belongs to the ovenbird family, a group of New World tropical birds that includes more than 230 species and that is 

如果这样补上一个that的话平行关系不就明朗了 这样正确答案仍是有与belongs还是includes歧义的问题

that在这里的省略是不是不太好呢