以下哪一些因素对商品质量有影响（） A.运输装卸 B.销售服务 C.质量法规 D.废

下列叙述错误的是（　　）

A．每种生物的细胞内，染色体数量是一定的

B．一条DNA分子上有许多基因

C．每个基因具有特定的遗传信息

D．克隆羊多莉是由代孕母羊C生出来的，所以长得像C羊

请填空：

Ⅰ．物质燃烧一般需要同时满足以下三个条件

a：______；b：______；c：______．

Ⅱ．可燃物燃烧的剧烈程度与许多因素有关

如d：氧气的浓度；e：可燃物与氧气的接触面积； f：可燃物本身的性质．

（1）下列实验或生活经验主要与上述哪个条件或因素相关，填入对应的序号

实验或生活经验	所选序号
石头不能被点燃，纸张能被点燃
劈成细条的木材比大块的木材燃烧更剧烈
燃着的酒精灯盖上灯帽后熄灭
木炭在空气中燃烧发红光，在氧气中燃烧发白光

（2）请运用化学知识解释成语：釜底抽薪______．

为生产线溶解罐手动加料？

为什么有焰燃烧时的火焰比无焰燃烧时稳定，不容易发生脱火？

The blue of the sea is caused by the scattering of sunlight by tiny particles suspended in the water. Blue light, being of short wavelength, is scattered more efficiently than light of longer wavelengths. Although waters of the open ocean are commonly some shade of blue, green water is commonly seen near coasts, especially in tropical or subtropical regions. This is caused by yellow pigments being mixed with blue water. Phytoplankton are one source of the yellow pigment. Other microscopic plants may color the water brown or brownish-red. Near the shore, silt or sediment in suspension can give water a brownish hue. Outflow of large rivers can often be observed many miles offshore by the coloration of suspended soil particles. Marine phytoplankton (Greek for "plant wanderers") are microscopic single-celled plants that include diatoms, dinoflagellates, coccolithophorids, green algae, and blue-green algae, among others. The growth of these organisms, which photosynthesize light, depends on a delicate balance of nutrient enrichment via vertical mixing, which is often limited by the availability of nitrogen and light. Diatoms are one-celled plants with patterned glass coverings. Each glass, or silicon dioxide box, is ornamented with species-specific designs, pits, and perforations making them popular with microscopists and, more recently, electron scanning microscopists.

The growth of phytoplankton is often limited by the availability of ______.

A．oxygen

B．hydrogen

C．nitrogen

D．carbon dioxide