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中国给英国点颜色瞧瞧！12架枭龙Block3阿根廷报价仅6亿美元 163.com

相比枭龙Block2，枭龙Block3在外观和气动布局方面基本没有任何区别，但是内在却得到了脱胎换骨的提升。Block number is a system to differentiate between groups of aircraft of the same type with minor variants.

Mach 1.0 is the speed of sound in air, so a plane flying Mach 2.0 is flying twice as fast as the speed of sound. The speed of sound is not a constant, but depends on altitude (or actually the temperature at that altitude). A plane flying Mach 1.0 at sea level is flying about 1225 km/h, a plane flying Mach 1.0 at 30000 ft is flying 1091 km/h (589 knots, 678 mph) etc. Speeds below Mach 1 are called subsonic, and above Mach 1.2 Supersonic.

飞机使用的喷气发动机在水平面上的最大推力和发动机的净重之比，称为飞机发动机的推重比。飞机在海平面最大静推力与飞机起飞重量之比，称为飞机的推重比。Thrust/weight2是loaded weight with 50% internal fuel.

The Chengdu J-20 (Chinese: 歼-20), also known as Mighty Dragon (Chinese: 威龙), is a single-seat, twinjet [双发动机], all-weather, stealth, fifth-generation fighter aircraft developed by China's Chengdu Aerospace Corporation for the People's Liberation Army Air Force (PLAAF). The J-20 is designed as an air superiority fighter with precision strike capability; it descends from the J-XX program of the 1990s.

The J-20 made its maiden flight on 11 January 2011, and was officially revealed at the 2016 China International Aviation & Aerospace Exhibition.The aircraft entered service in March 2017, and began its combat training phase in September 2017. The first J-20 combat unit was formed in February 2018.

The J-20 is the world's third operational fifth-generation stealth fighter aircraft after the F-22 and F-35.

Robert Gates downplayed the significance of the aircraft by questioning how stealthy the J-20 may be, but stated the J-20 would "put some of our capabilities at risk, and we have to pay attention to them, we have to respond appropriately with our own programs." In its 2011 Annual Report to Congress, the Pentagon described the J-20 as "a platform capable of long range, penetrating strikes into complex air defense environments." A 2012 report by the U.S.‐China Economic and Security Review Commission suggests that the United States may have underestimated the speed of development of the J-20 and several other Chinese military development projects.

After the deployment announcement, several analysts noted that experience that the PLAAF will gain with the J-20 will give China a significant edge [优势] over India, Japan, and South Korea, which have struggled to design and produce their own fifth-generation fighters on schedule. However, despite the failure of their indigenous projects, Japan and South Korea operate the imported F-35A, negating this potential technological disparity. 然而，尽管本土项目失败，日本和韩国仍在使用进口的F-35A，抵消了这种潜在的技术差距。If one thing negates another, it causes that other thing to lose the effect or value that it had. “大”日本和“大”韩民国没反超嘛。Both the US and Japan have lost F-35s to accidents. In September 2018, a US Marine Corps F-35B crashed in South Carolina, the first-ever crash of an F-35. In April 2019, a Japanese F-35A crashed into the Pacific Ocean off northern Japan, killing its pilot. 由于公知智商堪忧，我提醒下有些内容是从CNN抄来的。

Block or blocked may refer to:

• Toy block, one of a set of wooden or plastic pieces, of various shapes
• Compressed earth block, a building block or unit for construction
• Tower block, a high-rise building
• City block, the smallest area that is surrounded by streets
• Block (periodic table), a set of adjacent groups in the periodic table
• Block (meteorology), large-scale patterns in the atmospheric pressure field
• Block (blockchain), a segment of an open list of data records
• Block (programming), a group of declarations and statements treated as a unit
• Block-level element, in the HTML markup language
• Unicode block, a named range of codepoints in Unicode
• Engine block and cylinder block, the main part of an internal combustion engine
• Block (sailing), a single or multiple pulley used on sailboats
• Nerve block, or regional nerve blockade, any deliberate interruption of signals traveling along a nerve, often for the purpose of pain relief
• Block (basketball), when a defensive player legally deflects a shot
• Blocking (martial arts)

六级/考研单词: differentiate, thrust, liberty, superior, descend, maiden, aviation, exhibit, march, combat, tertiary, congress, penetrate, commission, unite, militant, deploy, struggle, despite, indigenous, import, negate, compress, construct, adjacent, segment, data, cylinder, sail, multiple, deliberate, interrupt, seldom, illicit, shot