豌豆的每个体细胞中有14条染色体，豌豆的卵细胞中有（ ）
A．7条染色体
B．14条染色体
C．21条染色体
D．28条染色体
答案：A
The spokesman said that this was a（n）____negotiation （谈判） because it solved a lot of problems between the two sides．
A．attractive
B．defensive
C．protective
D．productive
什么叫理论空气量、实际空气量？
