The navigational term SET OF CURRENT means（）. ["velocity of current in knots","direction from which the current flows","estimated current","direction toward which the current flow"]
测石层的原理是什么？
网络营销的定义是什么？从哪几个方面加强对网络营销的认识？
The movement of water away from the shore or downstream is called a(n)（）. ["reversing current","ebb current","flood current","slack current"]
如何提高二氧化碳浓度？
如何提高石灰石分解率？
