A tug is “in irons” when held in a fixed position by（）
A: the weight of its tow，its being anchored，or grounded
B: the weight of its towing hawser on the bottom
C: an adverse current
D: lack of power or an engine breakdow
A: the weight of its tow，its being anchored，or grounded
B: the weight of its towing hawser on the bottom
C: an adverse current
D: lack of power or an engine breakdow
举一反三
- When an object(物体) is being pushed or pulled horizontally, the normal force(法向力) N holding it against the surface it is on is simply its weight mg.
- A firm that shuts down temporarily has to pay A: its variable costs but not its fixed costs. B: its fixed costs but not its variable costs. C: both its variable costs and its fixed costs. D: neither its variable costs nor its fixed costs.
- FCL means the loading reaches its allowable maximum weight or full measurement.
- Its function is to keep the engine running smoothly between power strokes.
- The atomic weight of an atom, or the molecular weight of a molecule, is its mass relative to that of a(n) ________ atom. This is essentially equal to the number of protons plus neutrons that the atom or molecule contains.