债券和股票都是有价证券，都是投入公司的资金所有权证书，都以定期收取利息为条件。[ ]
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Martin set out ______ his homework as soon as he went home. [ ]
A. doing
B. for doing
C. to do
D. to doing
家禽早期胚胎发育与家畜早期胚胎发育的不同点是（）
A.卵裂
B.胚囊形成
C.原肠胚和胚层形成
D.三胚层分化及器官的形成期
E.胚胎附植
