— This is a great chance that many people don't have.
— I see. I'll cherish(珍惜) it.
A:achievement
B:opportunity
C:journey
—I learn it by working in pairs.
用最简分数表示。
12时=____天 37克=____千克
某同学依据对自家水稻田的实地调查,绘制了如下食物网简图。请你判断:
①∃x∈R,x≤0;
②至少有一个整数,它既不是合数,也不是质数;
③∃x∈{x|x是无理数},x2是无理数.