1. conundrum /kə'nʌndrəm/
n. 难题;复杂难解的问题；
e.g. Arranging childcare over the school holidays can be a real conundrum for working parents.
剑17-4-3: Ogilvie, who discovered the inventories in the archives of two German communities 30 years ago, believes they may hold the answer to a conundrum that has long puzzled economists.
注：puzzle v. 使迷惑；使困惑
2. groundbreaking /'ɡraʊndbreɪkɪŋ/
adj. 开创性的；创新的；
常见搭配：a groundbreaking discovery / work/ tech
e.g. This groundbreaking discovery changed the way people looked at the world.  
【phrase】break new/ fresh ground (in) 取得突破
e.g.The company has been breaking new ground in researching a cure for the deadly disease.
3. give lie to 
【phrase】证明…不实
常见搭配：give lie to the claim /notion that 观点/概念 
e.g. New methodologies give the lie to the notion that students who struggle with standardized tests lack intelligence. 
也就是说：考试成绩差就代表着不聪明这一观点是错误的。
剑17-2-3 Such examples give lie to the claim that ingenious, designing minds are responsible for human creativity and invention. 
同样地，创新也不完全来自于天才。
4. stifle /'staɪf(ə)l/
v. 扼杀;压制;抑止
e.g. Regulations on children stifled creativity.
e.g. Many businesses stifle innovation before it has a chance to blossom.
syn. suppress 
v. 克制住，忍住(哈欠、笑)
e.g. The lecture was as dull as dishwater but I had to stifle a yawn.
注：as dull as dishwater 非常乏味；无趣
5. gizmo /'gɪzməʊ/
n. a usually small mechanical or electronic device. 小装置；（往往不太知道名字的小型设备和产品）
搭配：a handy gizmo 便捷设备
a high-tech gizmo 高科技小发明
syn. gadget 
e.g. He broke the gizmo he uses to open and close his garage door. 
e.g. The store is full of gizmos like pagers and cellular telephones.