单项选择题
A.lack of toxicity
B.the multipurpose extinguishing ability
C.burn-back protection
D.cooling ability
单项选择题 All inspected vessels on unrestricted ocean routes must have equipment on board for testing an individual’s().
单项选择题 After an accident the victim may go into shock and die. What should be done to help prevent shock?()
单项选择题 According to the T-Boat regulations the reason for providing adequate ventilation for a battery storage area is to prevent().