可燃基

各种动物的数量在自然生态系统中[ ]

A．固定不变

B．缺少天敌时可无限增长

C．不受人为因素的影响

D．由于食物、空间及天敌的制约，不可能无限增长

关于先天性肥厚性幽门狭窄的叙述，正确的是（）

A.生后1～3周出现呕吐

B.呕吐进行性加重

C.可见胃型及蠕动波

D.钡餐示幽门呈"鸟喙状"

E.以上都对

产业竞争力的分析视角不包括（）。

A.产业业绩

B.产业结构

C.产业价值链

D.产业对外支配程度

男，54岁，四肢乏力伴麻木不适半年，根据所提供图像，最可能的诊断是（）

A．星形细胞瘤

B．神经源性肿瘤

C．室管膜瘤

D．脊膜瘤

E．血管母细胞瘤

Recycling Paper

The process of recycling paper can help to reduce deforestation and energy consumption on a significant scale. There are many different reasons why we should recycle paper products, and some of these are (26) in the paragraphs below.
Energy consumption will always be on the (27) as population levels grow, and so any manufacturing processes which help to reduce energy consumption are (28)
The Energy Information Administration (EIA) claim that there can be as (29) as a 40% energy saving when recycling paper over producing paper (30) the direct raw material.
Although recycling paper has many (31) , it also has its drawbacks. One of these drawbacks is that we cannot recycle the (32) paper product for eternity, as the fibers contained within the paper degrade over time, (33) their strength and length.
On (34) , an individual paper fiber can only be recycled a (35) of six times. Although this is a significant drawback, the six time recycling process will help to (36) a great deal of energy when you consider (37) much paper there is to be recycled.
If paper fibers can be recycled up to 6 times, and we recycled all paper products, this could help to (38) the intensity of deforestation for paper products up to a factor of 6.
With paper production said to (39) around 40% of harvested wood, and paper said to (40) around 90% wood, you can see how recycling paper is an important process for the (41) of our forests.
Today, the use of recycled paper products is on the increase, as more and more people begin to recycle paper (42) products around the home.
Although there are slight differences in the recycling processes of different (43) of paper products (e.g. corrugated, mixed paper, newspaper products), we are able to recycle just about any type of paper product around today.
The recycling logo helps to (44) a recyclable product and can also sometimes help to identify if the product contains any recycled material, in the form of a percentage. This helps a consumer to identify the (45) of recycling various products.

A. similar B. same C. different D. new