流体由l-1截面流入2-2截面的条件是()。
A、gzl+p1/ρ=gz2+p2/ρ
B、gzl+p1/ρ>gz2+p2/ρ
C、gzl+p1/ρD、以上都不是
参考答案:B
Their mother ________ dinner at the kitchen when a quarrel ________ among the children.[ ]
A. was preparing;was broken out
B. prepared;was broken out
C. was preparing;broke out
D. prepared;broke out
A. ,.
B. .
C.
D. , .