在我国古代农业生产发展过程中，从一定程度上直接破坏了生态平衡的是（)。A．圩田B．井田C．更名田D．屯

A. VLANs increase the size of collision domains.

B. VLANs allow logical grouping of users by function.

C. VLANs simplify switch administration.

D. VLANs enhance network security.

A. Layer 2 broadcast frames are processed by all devices on the same VLAN

B. Layer 2 broadcast frames are discarded by routers that connect to multiple VLANs

C. Layer 2 broadcast frames are relayed by routers to all connected VLANs

D. Layer 2 broadcast frames are relayed by switches to devices on the same VLAN

A. SONET and SDH both use time-division multiplexing.

B. An optical transport network system uses time-division multiplexing.

C. SONET and SDH both use wavelength-division multiplexing.

D. An optical transport network system uses wavelength-division multiplexing.

Which of the following statements about the mobile television is TRUE？

[A] Most people use it on a train in South Korea.

[B] Most people tend to use it at home in Japan.

[C] Some people choose to use it on a train in America.

[D] Many people dislike using it on bus in South Korea.

Which of the following statements about voice sites is INCORRECT？

A．They are in many ways similar to conventional websites.

B．Blind people may use them too.

C．They do not require a computer server.

D．Anyone who can speak and hear is able to use them through phone.

Which of the following statements is NOT true about understatement？

A.The English understatement isn’t actually very funny.

B.The English are renowned for their use of understatement because they invented it.

C.Their strict prohibitions on gushing, emoting and boasting require almost constant use of understatement.

D.Among the English, a well-timed, well-turned understatement only raises a slight smirk at best.

A. A new switch has no VLANs configured.

B. Connectivity between VLANs requires a Layer 3 device.

C. VLANs typically decrease the number of collision domains.

D. Each VLAN uses a separate address space.

E. A switch maintains a separate bridging table for each VLAN.

F. VLANs cannot span multiple switches.

A.VLAN 1 is the default Ethernet VLAN.

B.CDP advertisements are only sent on VLAN 1002.

C.By default, the management VLAN is VLAN 1005.

D.By default, the switch IP address is in VLAN 1005.

E.VLAN 1002 through 1005 are automatically created and cannot be deleted.

A. IS - IS is capable of supporting IPv4 and IPv6.

B. IS - IS is only capable of supporting IPv4 and CLNS.

C. IS - IS routers use ES - IS hellos (ESH) to establish and to maintain neighbor relationships.

D. IS - IS routers run the Bellman - Ford algorithm against their LSDBs to pick the best paths.

E. Level 1 routers learn about paths within the area of which they are a part.

F. Level 2 routers learn about paths both within areas and between areas.

Which of the following statements about the symbols is INCORRECT？

A．Both are used as the organization's official symbols.

B．Both are used regardless of religious significance.

C．The red cross was the organization's original symbol.

D．The red crescent was later adopted for use in certain regions.