在MIMO模式，哪个因素对数据流量影响最大（）A.天线尺寸 B.天线高度 C.发射和

配制标准缓冲液与溶解供试品的水，应是新沸过的冷水，其pH应为

A．3.5～5.5
B．4.0～6.5
C．5.5～7.0
D．5.5～8.0
E．6.0～8.0

钙、铁、锌、碘等元素对人体健康起着重要作用。下列说法中，正确的是[ ]

A．钙、铁、锌、碘均属于金属元素

B．人体缺钙易患骨质疏松症

C．含氟牙膏可以防龋齿，氟的元素符号是Fe

D．人体摄入营养元素越多越好

对更年期的叙述错误的是（）

A.男性也有更年期，在55～65岁

B.女性更年期较男性早10年

C.男性更年期症状较女性轻

D.女性有明显更年期综合征者达50%～90%

E.更年期综合征主要是主观感受

Most of the idle rich suffer unspeakable boredora as the price of their freedom from drudgery. At times they may find relief by hunting big game in Africa, but the number of such sensations is limited, especially after youth is past. 46. Accordingly more intelligent rich men work nearly as hard as if they were poor, while rich women mostly keep themselves busy with innumerable trifles of whose earth- shaking importance they are firmly persuaded.

47. Work is desirable as a preventive of boredom, for the boredom a man feels when doing necessary though uninteresting work is as nothing in comparison with the boredom he feels when having nothing to do. With this advantage of work another is associated, namely that it makes holidays much more delicious when they come. 48. Provided a man does not have to work so hard as to impair his vigor, he is likely to find far more zest in free time than an idle man could possibly find.

The second advantage of most paid work and of some unpaid work is that it gives chances of suecess and opportunities for ambition. In most work success is measured by income and while our capitalistic society continues, this is inevitable. It is only where the best work is concerned that this measure ceases to be the natural one to apply. 49. The desire that men feel to increase their income is quite as much a desire for success as for the extra comforts that a higher income can procure. However dull work may be, it becomes bearable if it is a means of buihliug up a reputation, whether in the world at large or only in one’ s own circle. Continuity of purpose is one of the most essential ingredients of happiness in the long run, and for most men this comes chiefly through their work.

50. The satisfaction of killing time and of affording some outlet, however modest, for ambition, belongs to most work, and is sufficient to make even a man whose work is dull happier on the average than a man who has no work at all. But when work is interesting, it is capable of giving satisfaction of a far higher order than mere relief from tedium. The kinds of work in which there is some interest may be arranged in a hierarchy. I shall begin with those which are only mildly interesting and end with those that are worthy to absorb the whole energies of a great man.

48. Provided a man does not have to work so hard as to impair his vigor, he is likely to find far more zest in free time than an idle man could possibly find.

在搭接接头中，正面焊缝的搭叠宽度（）。

A、＜5t（t为最小板厚）

B、≥5t（t为最小板厚）

C、≥6t（t为最小板厚）

D、≥8t（t为最小板厚）