标准的气象地面观测场的面积为（）米2，如确因条件限制也可适当按比例缩小，但不应当小于（）米2。
参考答案：25×25；16×16
After 5 days of fantastic space trip ,the two astronauts walked out of the spaceship, ______.
A．tired and happy
B．tired but happy
C．tiredly and happily
D．tiredly but happily
How long do you think the meeting will be lasted
