______ a good insulator(绝缘体) , rubber is often used in cables.

But later people developed a way of printing, _____rocks. 

At the crossing there is an arrow _______the direction to the Andrew Farm． 

----May I listen to the music here, Mr. White? ----Sorry , you’d better ____ it like that..

_____ from the top of the tower, the east foot of the mountain is a sea of rape flowers.