建筑照明设计时照度计算值和选定的照度标准值，允许有( )偏差。A．110% B．±

对于反应4HCl+MnO₂

△ .

MnCl₂+2H₂O+Cl₂↑，下列说法不正确的是（　　）

A．该反应是氧化还原反应

B．MnO₂是氧化剂

C．HCl是还原剂

D．若生成7.1gCl₂，则转移0.1mol电子

土地荒漠化日益危害人类的生存环境。全世界可耕地面积大约只有0.14亿平方千米，而荒漠面积比可耕地面积的2倍还多0.08亿平方千米。全世界荒漠面积约有多少亿平方千米？

下列关于对期货公司首席风险官的监管，说法正确的有（）。

A.中国证监会依法对首席风险官进行监督管理

B.中国期货业协会负责对首席风险官进行自律管理

C.证券交易所对首席风险官进行自律管理

D.中国证监会派出机构无权对首席风险官进行监督

.

CHICAGO (Reuters) - Smoking not only can wrinkle(起皱纹) the face and turn it yellow -- it can do the same to the whole body, researchers reported on Monday.

The study, published in the Archives of Dermatology, shows that smoking affects the skin all over the body -- even skin protected from the sun.

"We examined non-facial skin that was protected from the sun, and found that the total number of packs of cigarettes smoked per day and the total years a person has smoked were linked with the amount of skin damage a person experienced," Dr. Yolanda Helfrich of the University of Michigan, who led the study, said in a statement.

"In participants older than 65 years, smokers had significantly more fine wrinkling than nonsmokers. Similar findings were seen in participants aged 45 to 65 years," Helfrich's team added in their report.

The researchers tested 82 people, smokers and nonsmokers, taking pictures of the inner right arms. They ranged in age from 22 to 91 and half were smokers Independent judges decided how wrinkled each person's skin was.

When skin is exposed to sunlight, notably the face, it becomes coarse, wrinkled and discolored with a pale yellow tint, Helfrich's team wrote.

Several previous studies have found that cigarette smoking contributes to premature（过早的）skin aging as measured by facial wrinkles, the study said, but little has been done to measure the aging of skin not exposed to light.

The report did not discuss the mechanism involved but previous research has found that cigarette smoke, among other things, causes blood vessels（血管）beneath the skin to constrict（紧缩）, reducing blood supply to the skin.

Smoking can also damage the connective tissue that supports both the skin and the internal organs.

66. The best title for this passage would be_______.

A. The danger of smoking        B. A survey of smokers

C. Quit smoking for health       D. Smoking causes skin aging

67.  how wrinkled each person's skin doesn’t relate to_______.

A. the number of cigarettes a person smokes

B. the kind and characteristics of skin

C. how long a person smokes

D. how long skin is under sunlight

68. It can be inferred from the study _______.

A. smoking won’t make skin protected from the sun age

B. smoking will do damage to skin rather than other organs

C. smokers over 65 usually won’t worry about their skin

D. the age of smokers is not connected with the result of the test

69. From the passage smoking results in skin aging mainly because_____.

A. it will lower blood supply to skin.

B. it can make you feel tired

C. it can make skin come off

D. it can make blood run faster

70. The main purpose of the passage is to ______.

A. inform people about the result of the study

B. advise people to how to protect skin

C. warn people not to smoke again.

D. introduce a new way of avoid skin aging

当开挖面凸凹较大时，应按实际情况调整炮眼深度，力求所有炮眼（除掏槽眼外）眼底在（）。