reckon--v.计算,总计,估计,猜想,依赖
hand-held--手提式的
divert--v.转移, 转向, 使高兴
there's no way around the uncertainty--我们对这种不确定性无能为力
that means your choices can matter--这意味着你的选择很重要
accelerate--to speed up, increase the speed
arithmetic--n.算术,四则运算
burden--Something that is carried, especially a heavy load
conservation--the preservation and careful management of the environment and of natural resources
preservation--a process that saves organic substances from decay