If he is going for reavers and goons, you can cancel your +1 carapace upgrade if you really need the gas since goons and reavers is a do-or-die strategy for protoss.

• 如果他走的金甲和龙骑路线，当你真的需要气来应对神族金甲加龙骑的孤注一掷的策略的时候，你可以取消掉你的1级甲壳的升级。