For safe storage, the maximum allowable temperature to which refrigerant bottles should be exposed is ().
Diesel fuel is relatively safe to handle due to its low volatility, but the fumes will self-ignite and continue to burn steadily if the fuel is heated to the ().
The safe rate of bunkering heavy fuel oil is directly related to the ().
Safe speed is defined as that speed where().
The safe working load of the derrick is ().
The safe working load of the ()is 100 tons.
According to the passage, driving can be safe if ______.
Safe water buoys may show ONLY().
How is a safe water mark,that can be passed close aboard on either side,painted and lighted?()
R-12 is generally considered to be a safe, nontoxic, nonflammable, and non-explosive refrigerantIt can, however, become highly toxic when ().