一直立水坝中有一矩形闸门,宽10m,深6m,g是重力加速度,当水面在闸门顶上8m时闸门所受水的压力是( )kN
A. 180g
B. 300g
C. 660g
D. 760g
The time it takes one bacterium to become two bacteria is referred to as
A. the culture doubling time
B. the generation time
C. the mass doubling time
D. the incubation time
E. None of the above
Most pathogenic bacteria are
A. obligate aerobes
B. facultative anaerobes
C. microaerophiles
D. obligate anaerobes
E. None of the above
The growth rate of bacteria during the exponential phase of growth is
A. Zero
B. Increasing
Constant
Decreasing
E. Negative
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