A.50% B.65% C.85% D.95%
A.苗齡過(guò)長(zhǎng) B.苗齡過(guò)短 C.煉苗時(shí)間短 D.病蟲(chóng)害感染
A.高溫鍛煉 B.低溫鍛煉 C.增光鍛煉 D.增溫鍛煉