下列哪项属于严格意义上的B2B电子商务？（）

A、全剖视图

B、半剖视图

C、阶梯剖视图

D、局部剖视图

【填空题】AV Clip 16: Smoking and Mental DeclineAV 16 Smoking & Mental Decline.avi Watch the video clip three times and complete the following passage by filling in each blank with the word from the video clip. Cigarette smoking has long been associated with many serious health risks, including (1)______________ disease, stroke and cancer. Now new research shows that cigarette smoking may also be (2)________ to increase mental decline with age. Researchers from National Institute for Public Health and (3)____________ in the Netherland studied nearly 2,000 men and women aged 43 to 70 years. They gave (4)___________ cognitive tests, once at the beginning of the study, and then again five years later. The result shows that mental decline among smokers was 1.9 times greater for (5)__________ function, 2.4 times greater for mental (6)__________ and 1.7 times greater for overall cognitive ability. In the U.S., nearly 25% men and 18% women are still smokers. The researchers suggest that smokers who (7)________ their habit at any age may be able to postpone the (8)________ of cognitive decline as they grow older.

A、无启动子特异性

B、超长距离调控

C、反式作用

D、组合调控

A、倾听

B、共情

C、鼓励

D、指导

A、无

B、无

C、C. x(n) = R4((n))N

D、无

A、直线

B、圆

C、椭圆

D、双曲线

E、抛物线