2个氘核可聚变成一个氚核，放出4MeV的能量，写出核反应方程_____________当1kg氘完全聚变为氚时放出的能量为___________．
When a homeless man named Marcus wandered into Abigail’s Cafe asking for spare change, he didn’t get turned away. Looking at the man, the owner Abigail asked, “Why don’t you have a 41
设函数f(x)＝k为常数，e＝2.718 28…是自然对数的底数)． (1)当k≤0时，求函数f(x)的单调区间； (2)若函数f(x)在(0,2)内存在两个极值点，求k的取值范围．
To save him, we have to _______ as quickly as possible. A. make a decision B. get over C. end up D. take good care
下列有关血液循环知识的叙述，正确的是（ ）A． 可根据病人病情的需要，有针对性地进行成分输血，对于严重的贫血患者可首先输入血液成分中的红
某同学遇到一个难题：如图所示，要求不直接用手接触塑料板和鸡蛋，手头只有一个木棒，利用本节所学的知识，将鸡蛋放入水中。请你帮助该同学想
氢气作为21世纪极具开发前景的新能源之一，理由是 ①燃烧热值高②原料资源丰富③贮存和运输时安全性高④燃烧产物无污染 A.①②③ B.①②④ C.
