A.1倍 B.1.5倍 C.2倍 D.3倍
A.1節(jié)鏈長(zhǎng) B.2節(jié)鏈長(zhǎng) C.2節(jié)鏈長(zhǎng) D.4節(jié)鏈長(zhǎng)
A.鐘聲 B.手勢(shì) C.揚(yáng)聲器 D.報(bào)話(huà)機(jī)