A.不小于 B.不大于 C.小于 D.其他三個(gè)選項(xiàng)都不是
A.12k,12k±1 B.12k±1,12k C.24k,24±1 D.24k±1,24k
A.10-30% B.20-40% C.30-50% D.40-60%