1-take up/on challenge 接受挑战

It's the social media challenge taken up by thousands but the scientific claims behind it are nonsense.

2-gravitation 引力

3-footage 一段影片，片段

4-emulate 效仿

NASA said today was the only day a broom can stand up on its own because of the gravitational pull, posted a Twitter user in the US on Monday in footage which has been viewed millions of times and emulated by thousands.

5-tag 给……贴上标签

Although the earliest users of broomchallenge this year were from users in Mexico around 4 February, one of the first posts to tag NASA came from a Twitter user in Brazil on 8 February.

6-fact-checking 查证

7-circulate 流传，散布

8-spring equinox 春分

Fact-checking website Snopes says the broom challenge was widely circulated before in February 2012, and is another version of an egg-balancing trick which was attributed to the spring equinox.

9-astriphysicist 天文物理学家

Dr. Becky Smethurst, an astrophysicist from the university of Oxford, told the BBC she could not believe the misinformation being spread online.