单项选择题
There is not（）depth of water around the area centered at the lighthouse.
A.ample B.sufficient C.enormous D.incredible
单项选择题 The vessel was drifted off from her（）due to strong wind.
单项选择题 The use of the danger signal（）.
单项选择题 The two main types of load cells used in mooring tension gauges are（）.
