This room may be bugged. 这房间也许已被安上窃听器. Be careful what you say. I think the line is tapped. 说话要谨慎, 我想电话线上有人在窃听. He thinks before he speaks. 他言必经心. He chooses his words carefully. 他的谈吐严谨. A bird in the hand is worth two in the bush. 一鸟在手, 胜过双鸟在林. It's better for us to gain the upper hand. 我们占上风比较妥当. The truth is in the details. 要点都在细节上. Try to read between the lines. 要懂得弦外之音.
