And, after an initial cost of 60 bucks to buy the bacteria, which you'll never have to pay again, one cubic meter of bacterial sand would be about 11 dollars.
最初我们需要用60美元来买细菌， 之后你就不用再为细菌花钱了， 那样算下来的话一立方米带细菌的沙子 大约是11美元。