—Hi, Tom. Is your brother as active as you?      

—No, he's a quiet boy. He is _________.[ ]

A. less outgoing than me    

B. not so calm as I    

C. more active than I    

D. as outgoing as I

如图所示，弹簧测力计的示数为5N，动滑轮重为1N，则所用拉力F为______N，A物体的重为_______N，若自由端F拉出4m，则动滑轮上升_________m。