Defensive structures

For the defensive structure there was visitor the visitor name was Isaac. Isaac was teaching us bombs , dumb bombs and smart bombs. After we learned about exoplasive the exoplisive we learned are dynamite ,land bomb after we watch a video how does the shock wave start and exploded. After we had  a challange the challange we had to build a structure that made of 8+ straws and 1 piece  of paper after we had a swimming board Mr.Wong, Mr. Ogilvy and Isaac had to hit in both side to make the helicopter to die.