新闻背景：20多个国家和地区也有类似的区域

China's Air Defense¹ Identification Zone is aimed at controlling and monitoring incoming aircraft, in the interest of national security. But China is definitely not alone.

Currently, more than 20 countries and regions have their own Air Defense Identification Zone.

The first was established by the US and Canada in 1950, when they jointly² created a North American zone.

Japan’s air defense zone was set up by the US during its post-World War Two occupation of Japan. Since then, Japan has unilaterally expanded its zone twice, in 1972 and in 2010, pushing it further into the East China Sea. Japan’s Air Defense Identification Zone is now five times bigger than its national territory, extending as close as 100 nautical³ miles from China’s coastline.

China says Japan’s air defense zone is illegal, as it covers the Diaoyu Islands.

South Korea’s Air Defense Identification Zone was established in 1951 during the Korean War, also with the help of the US.

China’s newly launched defense zone overlaps⁴ with South Korea’s, and covers the Suyan Island, known as Ieodo in South Korea, a submerged rock claimed by Seoul.

 

1 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

2 jointly   

ad.联合地，共同地

参考例句：

• Tenants are jointly and severally liable for payment of the rent. 租金由承租人共同且分别承担。
• She owns the house jointly with her husband. 她和丈夫共同拥有这所房子。

3 nautical   

adj.海上的，航海的，船员的

参考例句：

• A nautical mile is 1,852 meters.一海里等于1852米。
• It is 206 nautical miles from our present location.距离我们现在的位置有206海里。

4 overlaps   

v.部分重叠( overlap的第三人称单数 )；（物体）部份重叠；交叠；（时间上）部份重叠

参考例句：

• The style in these two books largely overlaps. 这两本书的文体有许多处是一致的。 来自《现代英汉综合大词典》
• The new office overlaps the functions of the one already in existence. 新机构的职能与那个现存机构的职能部分重叠。 来自辞典例句