A.當(dāng)順時(shí)針轉(zhuǎn)動(dòng)時(shí),齒輪應(yīng)被鎖止
	B.當(dāng)順時(shí)針轉(zhuǎn)動(dòng)時(shí),齒輪應(yīng)靈活自如
	C.當(dāng)逆時(shí)針方向轉(zhuǎn)動(dòng)齒輪時(shí),應(yīng)被鎖止
	D.當(dāng)逆時(shí)針方向轉(zhuǎn)動(dòng)齒輪時(shí),應(yīng)靈活自如
	E.當(dāng)順時(shí)針轉(zhuǎn)動(dòng)時(shí),齒輪應(yīng)有阻滯
 
                            