机长座椅由几个马达控制？（）
A.1。
B.2。
C.3。
D.4。
参考答案：A
It is the first time that a developing country _______ the Expo, described as the Olympic Games of economy, science and technology．
A．is hosting
B．has hosted
C．hosts
D．will host
葡萄球菌食物中毒的好发食品是
A．肉制品，剩米饭B．鱼虾蟹贝类等C．禽蛋类D．面包，面条等食品E．臭豆腐，豆酱等
