A.3個 B.4個 C.6個 D.8個
A.1/6 B.1/3-1/5 C.2/3-4/5 D.1/2-2/3
A.全田穗數(shù)抽出20% B.全田穗數(shù)抽出30% C.全田穗數(shù)抽出80% D.全田穗數(shù)抽出10%