钢轨直线轨距标准规定为（）mm。A、1353 B、1435 C、1345 D、145

2010年10月1日“嫦娥二号”探月卫星沿地月转移轨道直奔月球，在距月球表面100km的P点进行第一次“刹车制动”后被月球捕获，进入椭圆轨道Ⅰ绕月飞行，之后，卫星在点又经过第二次“刹车制动”，进入距月球表面100km的圆形工作轨道Ⅱ，绕月球做匀速圆周运动，如图所示。则下列说法正确的是

A．卫星在轨道Ⅰ上运动周期比在轨道Ⅱ上长

B．卫星在轨道Ⅰ上运动周期比在轨道Ⅱ上短

C．卫星沿轨道Ⅰ经点时的加速度小于沿轨道Ⅱ经点时的加速度

D．卫星沿轨道Ⅰ经点时的加速度等于沿轨道Ⅱ经点时的加速度

泛制法制备丸剂的关键步骤是

A．粉碎
B．起模
C．成型
D．盖面
E．干燥

Now let’s look ourselves as a species in relation to ecosystem balance.Modern scientists believe that humankind, like other animals, evolved(进化) through millions of years of changes and adaptations to the environment and that our most direct evolutionary ancestor was probably an earlier species of the primate(monkey, ape) group. Despite this similarity with other creatures, however, the evolution of humankind differs from that of other species in one important and unique way.

In other species, evolution has led to specialization, both in the species abilities and in its place within the environmental structure. For example, the giraffe is much adapted to feeding on treetops, but it is also specialized and thus limited to feeding on trees and shrubs. Only with great difficulty can it bend down to graze on the ground. Similarly, the anteater is extremely well adapted to eating ants but is unable to catch or eat other animals. The same is true for countless other species.

For humankind it is opposite. Our evolution had led to a very generalized ability. Our highly developed intelligence and ability to make and handle tools mean that we can do almost anything. Humans evolved in such a way that we are able to move into every environment on Earth and even into space. No natural competitor offers great resistance, and other natural enemies such as disease have been controlled.

Said another way, we see in humankind a great imbalance between biological potential and environmental resistance. The result is the rapidly increasing world population, frequently referred to as the population explosion. Further, to support our growing population, natural ecosystems are being increasingly displaced by human habitations, agriculture, and other human supporting activities.

小题1:From the passage we can infer that in the course of evolution _______.

A．humankind is very important to earlier species, such as the primate group

B．human beings are limited by the environment while animals are not

C．human beings become more and more different from each other

D．humankind has experienced a generalization rather than specialization in ability小题2:According to the passage, primate includes such animals as _______.

A．monkeys and anteaters

B．tigers and apes

C．apes and monkeys

D．monkeys and giraffes小题3:According to the passage, evolution has made it possible for humans to _______.

A．increase the population

B．resist natural offers

C．go to the moon

D．cure all diseases小题4:According to the author, imbalance between biological potential and environ mental resistance has resulted in _______.

A．the population explosion

B．the destruction of human habitations

C．the growth of natural ecosystem

D．the specialization of humans

长途资费标准和分时段优惠办法自2001年2月21日零时执行，固定优惠时段为00：00—7：00，不区分工作日和节假日；（）的长途电话优惠执行时间按当地时间，即向后顺延2小时。

A.西双版纳；

B.新疆；

C.西藏；

D.青藏；

融资租赁交易一般至少签订《融资租赁合同》和《购买合同》，其中《购买合同》的决策人是（），《购买合同》的买方是（）。出卖人根据《购买合同》的约定，向（）交货。

A.承租人、出租人、承租人

B.出租人、承租人、出租人

C.承租人、承租人、出租人

D.出租人、出租人、承租人