在世界上首先培育成籼型杂交水稻的是_______，他被国际农学界誉为“杂交水稻之父”。
袁隆平
Which of the following statements regarding exchange-traded derivatives is FALSE Exchangetraded derivatives :()
A. are illiquid and have secondary markets.
B. are standardized contracts.
C. often trade in a physical location.
为了对喷油器的性能进行检查，主要进行的项目是（）
A.密封性检查
B.喷油压力检查
C.喷雾质量检查
D.喷雾锥角检查
