人在步入带电地面时，这种会触电的电压称为（）。A、单相电压 B、两相触电电压 C、接

有以下程序： #include ＜stdio.h＞ main() { int s, t, A=10; double B=6; s=sizeofA.; t=sizedB.; printf("%d, %d\n", s, t); } 在VC 6.0平台上编泽运行，程序运行后的输出结果是______。

A．10,6

B．4,4

C．2,4

D．4,8

飞机称重中如果以起落架机轮为称重点，要释放刹车的目的是什么？（）

A.减少秤盘上侧向载荷对称重读数的影响。

B.调整飞机的水平姿态。

C.使机轮稳妥地停留在秤盘上。

D.调整飞机的前后位置。

国民生产总值等于国内生产总值加上( )。

A．折旧
B．财产收入
C．国外的净要素收入
D．净出口

Our brains could be hard-wired to be male or female long before we begin to grow testes(丸)or ovaries(卵巢)in the womb. This discovery might explain why some people feel trapped in a body that’s the wrong sex, and could also lead to tests that reveal the true "brain sex" of babies born with ambiguous genitalia(生殖器).
Till now, the orthodoxy among developmental biologists has been that embryos develop ovaries and become female unless a gene called SRY on the Y chromosome is switched on. If this gene is active, it makes testes develop instead. This switch is seen as the key event in determining whether a baby is a girl or a boy. Only after the gonads(性腺) form and flood the body with the appropriate hormones, the theory goes, is the sex of our minds and bodies determined.
But in a study of mice, a team at the University of California, Los Angeles, has now found that males and females show differences in the expression of no fewer than 50 genes well before SRY switches on. "It’s the first discovery of genes differentially expressed in the brain, "says Eric Vilain, who led the UCLA team. "They may have an impact on the hard-wired development of the brain in terms of sexual differentiation independent of gonadal induction."
Vilain is presenting details of seven of the 50 genes to the annual meeting of the American Society of Human Genetics in Baltimore this week. Three of these genes are dominant in females and four are dominant in males. The next step for Vilain and his team will be to show that the genes in question really do influence brain sexuality—and not just in mice. This is likely to be a much tougher proposition than merely showing there are differences in expression.
But if the findings are confirmed, they could one day yield blood tests that allow doctors to establish the brain sex of babies born with genitalia that share features of both sexes. At present doctors and parents have to guess which gender to assign for surgical "correction".

What has been found by the study at UCLA

A．We human beings have fewer than fifty genes.

B．Males and females have similar expression genes.

C．Differences in the expression of genes appear before SRY switches on.

D．Sexual differentiation depends mainly on gonadal induction.

按货架构造形式可将自动化仓库分为（）自动化仓库。

A.单元货架式

B.垂直循环式

C.水平循环式

D.贯通式