The third phase, to test whether the vaccine prevents real infection, has not yet been carried out, as there has been no massive spread of H5N1 influenza in people.
The Normandy invasion began with overnight parachute and glider landings, massive air attacks, naval bombardments, and an early morning amphibious phase began on June 6.
攻占诺曼底由整夜的降落伞和滑翔机空降、大规模的空袭、海军轰炸和6月6日早晨展开的两栖作战阶段组成。
3
You can detect flaws even in early iterations rather than during a massive testing phase at the end.