Hi @zacky07 Thank you for joining [The Steemit Crypto Academy Courses](https://steemit.com/trending/hive-108451) and participated in the Homework Task. |Review Visit Level|Task Remark| |--|--| |First|Completed| |Your Overall Performance In this Task| |--| |Criteria|Strongly Agree|Agree|Disagree| |--|--|--|--| |Task Meet Expectations|✔️||| |Task Lenght Sufficient|✔️||| Task Presentation|✔️||| Plagiarized Content|||✔️| Content was Clear & Understandable.|✔️||| The Quality & Material Of Task Helpfull (Content, Images).|✔️||| Extra Efforts On Task.|✔️||| |Comments, Guidance, Feedback, Suggestions| |--| |Overall your performance was great. In Practical, Blockchain, you first mentioned what block contains, then mentioned that the block became invalid and also the next blocks affected, but the information is not clear how they become invalid, while changing the date what actually makes them invalid, then what actually changed to become valid after mining, what is the Blockchain mechanism behind this. If you could try to explore this more then it will look more informative.| Grade Achived|Verification (Done, Hold)| |--|--| 8|Done| ***Total*** / ***8/10*** Your Homework Task verification has been done by @Stream4u, hope you have enjoyed and learned something new. Thank You. @stream4u [*Crypto Professors : Steemit Crypto Academy*](https://steemit.com/cryptoprofessor/@steemitblog/the-steemit-crypto-academy-the-first-crypto-professors) https://cdn.steemitimages.com/DQmQB5ngkryWHkHYkkbM5NDxJXmakNA611it3PJERdwmbpB/image.png #affable https://cdn.steemitimages.com/DQmdUh4X5gNtnPTAvgeu1Dvjvnh2zWk6KaqEKvzUYLqBnAf/image.png