电子商务正在以越来越快的速度发展的原因是（） ["计算机的广泛应用","网络的普及和成熟","信用卡的普及应用","电子安全交易协议的制定"]
怎样防止冷却水管系统的泄漏？
什么是玻璃棉？超细玻璃棉的堆密度，定额是按什么考虑的？如与实际有出入应怎样调整？
绝热工程中：若采用钢带代替捆扎线时，总长度不变，重量应怎样换算？
Which statement about the hospital space on a cargo ship is TRUE（）. ["The hospital may be used for disciplinary confinement if it is not being used for treatment","The hospital space must have both a bathtub and shower","A hospital is required on all vessels with a crew of 12 or more if it makes overnight voyages","If a ship has a crew of forty-five who do not have their own room，the hospital must have four berth"]
怎样防止冷却水管件及冷却水管的冻裂？
