To answer the first part of your question, I'd like to say that our studies were very extensive.
你问题的第一部分,我要说的就是我们的研究非常广泛。
It was noticed that there were no signs or warnings on the supply lines that ran round the port.
人们这才注意到,铺设在码头周围的供应管道上没有贴标签或告示。