广播式自动相关监视（ADS--B）是通过（）实现定位的。
A、GPS
B、一次雷达
C、二次雷达
D、VHF
参考答案：A
11. It is natural that____student doesn't know some answers to____questions raised by their teachers.
A．a;a
B．a;the
C．the;a
D．the; the
如何通过标签查看种子质量？
