求助语法题

Tino

By using their trunks, elephants can tell the shape of an object and ........ is rough or smooth, or hot or cold.
(A) it
(B) whether it
(C) how
(D) since it

IcePoint

名词从句 B

Tino

多谢了,可是whether和and都是连词呀,这里具体是怎么划分句子结构的呀?

Luffy

以下是引用Tino在2003-11-23 12:39:00的发言：
By using their trunks, elephants can tell the shape of an object and ........ is rough or smooth, or hot or cold.
(A) it
(B) whether it
(C) how
(D) since it

elephants(主语） can tell（谓语） the shape of an object（宾语） and ........ is rough or smooth, or hot or cold（句子做宾语）.   and 连接两个宾语。