A.自由長(zhǎng)度 B.安裝長(zhǎng)度 C.工作長(zhǎng)度 D.壓實(shí)長(zhǎng)度
A.30° B.60° C.120° D.180°
A.1/2倍 B.2/3倍 C.3/4倍 D.7/8倍