【单选题】从离心泵 Q-N 曲线上可看出,在 Q=0 时, N ≠ 0, 这部分功率将消耗在水泵的机械损失中,变为( )而消耗掉,其结果将使泵壳内水温上升,泵壳、轴承会发热,而严重时会导致泵壳变变型。所以,起动后出水阀门不能关太久。
【单选题】Does your sister like Chinese food or _______ food?
【单选题】How often does the man eat Chinese food?
【单选题】______ they ______ Chinese food? [ ]
【单选题】下列动物中,属于诱发性排卵的是: ( ) ?
【单选题】What does 'the instinct to eat fat has begun to work against us' mean?
A.
Fast food does offer enough fat to our bodies.
B.
Fast food makes the instinct decrease.
C.
Fast food offers too much fat to absorb.
D.
The instinct refuse to receive the fat in fast food.
【单选题】从离心泵Q-N曲线上可看出,在Q=0时,N≠0,这部分功率将消耗在水泵的机械损失中,变为( )而消耗掉,其结果将使泵壳内水温上升,泵壳、轴承会发热,严重时会导致泵壳变变型。所以,起动后出水阀门不能关太久。