某果园的苹果树大都产量较低、果实品质欠佳.若要尽快更新为优质苹果树,你的合理化建议是( )
A:种子繁殖
B:全部换栽
C:果枝扦插
D:果枝嫁接
如图,点P在以MN(南北方向)为直径的⊙O上,MN=8,PQ⊥MN交⊙O于点Q,垂足为H,PQ≠MN,弦PC、PD分别交MN于点E、F,且PE=PF.
His father works a policeman at a police station.