1. Days and days of meticulous preparation have gone into conducting this important experiment.2. Rigorous testing was done to make sure the antibody would truly work to fight the virus.
 rigorous meticulous very carefulrigorous = meticulous = 嚴密/縝密/嚴謹例如:rigorous testing = 嚴密/縝密/嚴謹的測試rigorous 也有嚴格的意思。very careful = 非常小心，就是白話的說法
The moerator of the meeting is not here yet. Does that mean the meeting will not be happening?下一題 - 一晚要價 f我要發問