Elephants have their own way to tell the shape of an object and _______ it is rough or smooth.

A. /                               B. whether                    C. how                         D. what

Elephants have their own way to tell the shape of an object and ________ it is rough or smooth.     

A. 不填                B. whether                C. how                D. Which

Elephants have their own way to tell the shape of an object and _______ it is rough or smooth.

A. / B. whether ?

C. how D. what?

Elephants have their own way to tell the shape of an object and ________ it is rough or smooth.     

A. 不填      B. whether        C. how       D. Which

Elephants have their own way to tell the shape of an object and _______ it is rough or smooth.

A. /                               B. whether                     C. how                    D. what