What are the factors that affect fertility in the environment（）

A .  codec B .  link speed C .  Layer 2 encapsulation D .  packet overhead （IP/UDP/RTP） E .  link delay F .  total number of simultaneous calls that are allowed

A . A voice packet is sent via multiple fixed-length cells; a portion of the last cell is padding, requiring more bandwidth. B . ADSL typically uses PPPoE encapsulation, which adds additional overhead to each voice packet. C . A voice packet is sent via multiple fixed-length cells; each cell has about 10% Layer-2 header overhead.  D . IPSec requires additional overhead for the header and hash.  E . ADSL carrier band requires additional bits to be carried over the wire to the DSL Access Concentrator.

A .  low optical powe B .  high optical power C .  few optical channels D .  many optical channels E .  low chromatic dispersion F .  high chromatic dispersion G .  too much power differential in the optical channel

A . fiber dispersion B . signal attenuation C . transmitter power D . amplifier bandwidth E . receiver dispersion tolerance

A . radio communications that are available B . maximum speed of your vessel C . temperature D . current

A . CPU utilization B . where Netflow data will be sent C . number of devices exporting Netflow data D . port availability E . SNMP version F . WAN encapsulatio

A . low optical power B . high optical power C . few optical channels D . many optical channels E . low chromatic dispersion F . high chromatic dispersion G . too much power differential in the optical channel

A . codec B . link speed C . Layer 2 encapsulation D . packet overhead （IP/UDP/RTP） E . link delay F . total number of simultaneous calls that are allowed

A . Effect of the moon's gravity B . Fetch C . Wind velocity D . Length of time a wind has been blowing

A . number of product features B . return on investment C . competitiveness D . regulation E . day one costs F . availability of budget

A .  fiber dispersion B .  signal attenuation C .  transmitter power D .  amplifier bandwidth E .  receiver dispersion tolerance

A、Unit price. B、Quantity. C、Ways of payment. D、Discount.

A．low employment B．personal choice C．tax revenue D．home countries

A．time and age B．ability and sex C．talent and age D．time and motivation

A．Wealthy gardeners liked to compete for rare plants. B．The number of people with disposable income was growing. C．Tulip bulbs were initially cheap and easy to obtain. D．Tulips in the wild bloomed in unusual color combinations. E．The tulip market was not regulated by the government. 此题为多项选择题。

A．Power. B．Skill. C．Patience. D．Weapons.

A．the weather usually follows a weekly cycle. B．when people stay at home, they are careful with pollutants production. C．air circulation acts in different manners because of deliberate human interference. D．different activities on weekdays and weekends have imposed effect on the air.

A. Unemployment rate of workers. B. Most workers' flat incomes. C. Corporate profit. D. Low operation cost.