A major health hazard of the product tert-butylamine is that it （）. can be absorbed through the skin。 causes irreversible damage to eye tissue。 is a very unstable product。 All of the above。
简述淋巴管回流受阻。
频率规划中4x3复用模式是指每个站（）个小区，每（）个站进行复用。
A low HDOP (Horizontal Dilution of Precision) number such as 2 indicates a （）. poor fix。 good fix。 poor signal quality。 good signal quality。
救生艇配备的海锚索和回收索的长度应不少于10米。
A low pressure annular preventer which is used to direct flow of kick fluids away from the rig floor is called a （）.
