[单项选择]The very north and south regions are covered with ice and snow.
A. areas
B. rocks
C. mountains
D. districts

[单项选择]The polar regions are generally covered with ice and snow.


A. areas
B. rocks
C. mountains
D. seas

[单项选择]Experts believe that North Korea and South Korea ______ reunite one day.
A. may
B. have
C. had
D. are able to

[单项选择]North Island, South Island, and Steward Island are the three large islands that ______ the country of New Zealand.
A. compact B. compose C. comply D. comprise

[单项选择]Which is ______, North America or South America
A. biggest
B. the biggest
C. more biggest
D. bigger

[单项选择]North America borders both the North ______ and the North ______.
A. Arctic Ocean, Indian Ocean
B. Atlantic Ocean, Pacific Ocean
C. Atlantic Ocean, Arctic Ocean
D. Indian Ocean, Pacific Ocean

[单项选择]Ann covered it with Christmas lights.

[判断题]General average and salvage charges are covered both in FPA and WA coverage. ( )

[单项选择]The potential profits from writing a covered call position on a stock are: （）
A. less than potential profits of a short call. 
B. limited to the premium plus stock appreciation up to the exercise price. 
C. limited to the premium.

[单项选择]In temperate regions the growth rings on turtles’ epidermal plates reflect seasonal variations in growth.（　）
A. indicate
B. stimulate
C. include
D. prevent

[单项选择]The saguaro, found in desert regions in the southwestern United States,......cactus in the world. (a)is the largest (b)the largest (c)that is the largest (d)the largest that is a

[单项选择]

We have already covered the topic of network addresses. The first （） in a block (in classes A，B，and C) defines the network address. In classes A，B，and C，if the hostid is all ls， the address is called a direct broadcast address. It is used by a.（） to send a packet to all hosts in a specific network. All hosts will accept a packet having this type of destination address. Note that this address can be used only as a （） address in an IP packet. Note also that this special address also reduces the number of available hostid for each netid in classes A，B，and C.
In classes A，B，and C，an address with all is for the netid and hostid (32 bits) defines a（） address in the current network.A host that wants to send a message to every other host can use this address as a destination address in an IP packet. However，a router will block a packet having this type ofaddress to confine the broadcasting to the （） network. Note that this address belongs to class E.

The first （） in a bl
A. datagram
B. function
C. address
D. service

[单项选择]In mountainous regions, much of the snow that falls is compacted into ice.
A. hauled
B. compressed
C. compiled
D. harnessed