hang in the air，suspend in midair，be divorced from reality ；

[例句] 就剩下我用指尖扒着悬空在几百英尺高的地方。 I was left hanging by my finger-tips over a drop of hundreds of feet.

[例句] 他正一动不动地站在这悬空巨石的顶端,凝着神,敛着翅. He stands firmly at the top of a gigantic rock gazing afar.

emptiness，void，aeriality，inanity；

[例句] 她分手时说的话让他感觉空虚孤独。 Her parting words left him feeling empty and alone.

[例句] 之后对生活产生的影响可能会是空虚感和沮丧感。 The result later in life may be feelings of emptiness and depression.

fancy，idle dream，daydream，fantasy，dream；

[例句] 有理想，却不愿为之努力，那只是空想。 There's no point having wishes if you don't at least try to do them.--Sally Nicholls

[例句] 他在虚幻的空想中虚度了光阴。 He idled the time away in dreamy thought.

be in debt，be in the red，debt，spend more than one makes，red ；

[例句] 这座电影院亏空50万英镑。 The theatre is £500,000 in the red.

[例句] 这家公司亏空3000美元. The company had a deficit of ＄3000.

[讯] space，absentee，dead number ；

[例句] “ 传号 ” 或 “ 空号 ” 条件是由两条线之间的电压来表示的. The " mark " or'space " condition is represented by the voltage between two wires.

[例句] 打过, 但那个号码是空号. Yes, but the number's no longer in service.

cavitation，cavitate ；

[例句] 空化(或称气穴)是流体系统中常见的现象,它显著地影响着流体管路的瞬态特性. It an obvious effect on the transient characteristics of the fluid system.

[例句] 空化水洞是研究空化现象的实验设备之一. Cavitation water tunnel is one of experimental facilities studied cavitation phenomenon.

vacant position，vacancy，opening ；

[例句] 他们可能会挖她去填补执行制片人这一空缺职位。 They may headhunt her for the vacant position of Executive Producer.

[例句] 空缺的世界拳击理事会次轻量级头衔被取消了。 The vacant W.B.C. junior-lightweight title has been called off.

territorial sky，territorial air space，airspace ；

[例句] 这家航空公司还未获得飞越坦桑尼亚领空的许可。 Permission has not yet been granted for the airline to overfly Tanzania.

[例句] 飞机飞离了英国领空。 The plane left British airspace.

empty talk，empty words，idle talk，hollow words，bosh ；

[例句] 他禁不住想所有这些不过是“画饼充饥”的空话而已。 He can't help thinking it's all just "pie in the sky" talk.

[例句] 盟军领导人说他们要的是行动，不是空话。 Allied military leaders have said they want actions, not words.

evacuate，exhaust，pumpdown，pump-out；

[例句] 你能设法抽空出席这个交际会,我很高兴. I " m so glad that you were able to come to this party.

[例句] 你甚至可以抽空休息几小时，商量一下的话没准还能偶尔不用上晚班。 You can even snatch a few hours off, and perhaps negotiate the occasional night off too.

opening，blank，area，lawn，clearing；

[例句] 在新建的远郊住宅区之间还有空地可以盖房。 There is room for infill between the new outer suburbs.

[例句] 他们拆掉户籍登记处后，那里留下了一片空地。 They'd pulled the registry office down which then left an open space.

[生理] jejunum ；

[例句] 远端十二指肠及空肠仍处于脊椎右侧。 The distal duodenum and jejunum remain on the right side of the spine .

[例句] 远端十二指肠及空肠仍处于脊椎右侧. The distal duodenum and jejunum remain on the right side of the spine.

[体] somersault，flip ；

[例句] 他的空翻技巧 、 平衡技术 、 灵活性以及创新性简直太棒了. His skills in aerial tumbling, balance, flexibility, and originality are really marvelous.

[例句] 蹦床有其专门术语,如 “ 双空翻并转体一周 ” 、 “ 前空翻并转体2.5周 ”. Trampoline has its own terms such as " fliffis " and " Randolphs. "

fail to get or achieve what one wants，fail to meet sb. one intends to meet，come away empty-handed，fan the air ；

[例句] 昨天我去找他, 又扑空了. Yesterday I went to see him, but again he wasn't home.

[例句] 给了若干个与T-1LF拓扑空间等价的条件. The equivalent conditions in ? T - 1 L ? fts are given in this paper.

[航空] airspace ；

[例句] 机群将被迫在国际空域飞行. The squadron would be forced to keep to international skies.

[例句] 夹带率应几乎随自由空域高度成指数递减. The entrainment rate should closely decrease exponentially with freeboard height.

empty talk，doctrinairism，ideology ；

[例句] 那只不过是空论. That is mere talk.

[例句] 选举将取决于竞争力而非空论 ( 乔治F. 威尔 ) The election would turn not on ideology but on competence ( George F. Will )

headroom，freeboard，clearance ；

[例句] 前舱有6英尺高的净空，也有足够的空间供人站立和穿衣服。 The forecabin, with 6ft head-room, also has plenty of room to stand and get dressed.

[例句] 这座桥梁下面的净空高度不够,公共汽车不能通行. There is not enough headroom for buses to go under this bridge.

interlunation，vacuum，neutral，free position ；

[例句] 格雷厄姆把货车挂到空挡，自己跳到马路上。 Graham put the van in neutral and jumped out into the road.

[例句] 他们加大油门，再切入空挡，随后没大响动地滑下山坡。 They picked up momentum, then slipped into neutral and coasted quietly down the slope.

empty ；

[例句] 林口火力发电厂内的煤列空车,附有尾灯(牌),免守车. Empty coal freight vehicles in Lin - Kou Power Plant terminal indicators.

[例句] 这是辆空车 吗 ? Is this car vacant?

“short selling”，bear，short sale，selling short，oversell ；