藤球是实心还是空心的？
参考答案：
空心的。
下列各组数中，是勾股数的一组是（ ）
According to _______announcement by Guangzhou Price Bureau, _______new measures which have been taken recently are expected to cut the operation costs of each taxi driver by 1280 yuan.
A．the; /
B．an; the
C．/; the
D．an; /
