从谈判内容上看，容易形成谈判僵局的主题是（）
A.价格
B.质量标准
C.违约责任
D.履约地点
参考答案：A
在火箭竖直向上加速运动的过程中，宇航员对其座椅的压力______（选填“大于”或“小于”）宇航员的重力，宇航员处于______（选填“超重”或“失重”）状态．
Your vessel has been damaged and is taking on water，but you do not require immediate assistance. You would preface a message advising other vessels of your situation with（）.
A.Mayday-Mayday-Mayday
B.Pan-Pan (3 times)
C.Securite-Securite-Securite
D.SOS-SOS-SOS
