Compared to the amount of concentrated foam liquid used，the amount of low expansion mechanical foam produced is（）.

A . The high discharge pressure of the rotary pumps permits a larger volume of fluid per unit time than the reciprocating pump B . Rotary pumps are capable of pumping more fluid than reciprocating pumps of the same weight C . Rotary pumps occupy only one-half the space of reciprocating pumps D . Rotary pumps eliminate discharge slippage of the pumped liquid, while this does not hold true for a reciprocating pum

A . dischargeendbeingsmallerthanthesuctionend B . smallsizeofimpeller C . lackofmovingparts D . easeatwhichthewearingringsmaybechanged

A . variable B . the same C . lighter D . heavier

A . shorten the hawser or increase the tug's speed B . lengthen the hawser or reduce the tug's speed C . place your tug in irons D . make a sharp tur

A . less even torque B . higher cylinder head temperatures C . fewer power strokes per revolution D . greater weight/size requirement

A . a specific barometric pressure B . a specific temperature C . a specific wind speed D . any time

A . be more suitable for river and harbor navigation B . provide better range performance on low lying targets during good weather and calm seas C . have a wider horizontal beam width D . have more sea return during rough sea conditio

A . Humidity B . Temperature C . Precipitation D . Wind

A . sample B . receipt C . record D . quantity

A . return on investment (ROI) B . net present value (NPV) C . discounted cash flow (DCF) D . B and C E . All of the above.

A．are reorganized more often B．give more lectures to students C．qualify more technical graduates D．revolutionize many walks of life

There is some relationship between age and children's characteristic reaction to divorce. As the child grows older, the greater is the likelihood of a free expression of a variety of complex feelings, an understanding of those feelings, and a realization that the decision to divorce cannot be attributed to any one simple cause Self-blame virtually disappears after the age of 6, fear of abandonment diminishes after the age of 8, and the confusion and fear of the young child is replaced in the older child by shame, anger, and self-reflection. Gender of the child is also a factor that predicts the nature of reaction to divorce, the impact of divorce is initially greater on boys than on girls. They are more aggressive, less compliant, have greater difficulties in interpersonal relationships, and exhibit problem behaviors both at home and at school. Furthermore, the adjustment problems of boys are still noticeable even two years after the divorce. Girls' adjustment problems are usually internalized rather than acted out, and are often resolved by the second year after the divorce. However, new problems may surface for girls as they enter adolescence and adulthood. How can the relatively greater impact of divorce on boys than on girls be explained？ The greater male aggression and noncompliance may reflect the fact that such behaviors are tolerated and even encouraged in males in our culture more than they are in females. Furthermore, boys may have a particular need for a strong male model of self-control, as well as for a strong disciplinarian parent. Finally, boys are more likely to be exposed to their parents' fights than girls are, and after the breakup, boys are less likely than girls to receive sympathy and support from mothers, teachers, or peers. Temperamental, irritable kids have difficulty adapting to parental divorce because A．they care too much about the life change. B．the great stress of their families diminishes their ability. C．they tend to lose temper easily and are sensitive to the life change. D．they are faced with more parents' fights than the relaxed, easygoing children.

A、The mean of the individual random variables B、The variance of the individual random variables C、The correlation between individual random variables

A．identify whether you yourself are safe or not B．take a quick,calm and controlled approach C．get to the emergency spot immediately D．possess some first-aid skills 此题为多项选择题。

A、Increase a shareholders wealth by a greater amount. B、Increase a shareholders wealth by a lesser amount. C、Have a relative impact that depends on the tax treatment of the two alternatives.