评判下面说法的对(√)错(×)。

( ) 1. A zebra has no stripes.                      

( ) 2. A fish lives in the water.                  

( ) 3. An ostrich has two wings, but it can't fly.  

( ) 4. An elephant has a short trunk.              

( ) 5. A snake has no legs.                        

( ) 6. A camel has humps.                          

( ) 7. A rabbit has a short tail and long ears.    

( ) 8. Giraffes and deer are different.            

( ) 9. Pandas and bears are different.              

( ) 10. Horses and zebra are different.            

判断下列四句话的对错,并且说出理由:

(1)离子键只存在于离子化合物中

(2)离子化合物一定含离子键

(3)离子化合物中一定不存在分子

(4)离子化合物不一定含有金属元素