A.當(dāng)行星架被動時必為升速擋 B.當(dāng)行星架主動時必為升速擋 C.當(dāng)太陽輪主動時必為升速擋 D.當(dāng)太陽輪主動時必為降速擋
A.甲正確 B.乙正確 C.甲乙均正確 D.甲乙均不正確