“这里有鲜花，也有陷阱；这里有助人的大侠，也有吃人的魔鬼；这里有善良的小白兔，也有凶恶的大灰狼。”这形象地告诉我们网络交往（    ）

①是一把双刃剑，有利也有弊 ②要有辨别能力

③要以健康的心态对待      ④为了交往，在所不惜

A．①②④

B．②③④

C．①③④

D．①②③

The basic concept of GMDSS is（）.

A.Search and rescue authorities ashore will rapidly received an distress alert and acted upon

B.SAR units will be rapidly alerted to a distress incident and assist in a coordinated SAR operation

C.Ships navigating in the immediate vicinity of the ship in distress will rapidly alerted to the alert and give their help accordingly

D.The RCC will rapidly alerted to a distress alert through satellite and terrestrial communication techniques and conducted a rescue operation immediately