【简答题】How much food, fresh
water and energy is predicted to be used in the future?
【简答题】How much energy is wasted before it arrives to fuel a desk lamp()
【简答题】已知f(x)的值域是 ,求函数 的值域.
【判断题】如果一种商品满足了一个消费者坏的欲望,说明该商品具有负效用。
【单选题】According to the news, what kind of energy would provide much needed energy inputs, but is too limited for mass use?
【判断题】如果一种商品满足了一个消费者坏的欲望,说明该商品具有负效用。
【简答题】已知函数 (1)若 的定义域是 ,求实数 的取值范围及 的值域; (2)若 的值域是 ,求实数 的取值范围及 的定义域
【单选题】How much energy could 1 recycled tin can save? ( )
A.
Enough to power a cell phone for 18 hours.
B.
Enough to power a TV for 3 hours.
C.
Enough to power lamp for 6 hours.
D.
Enough to power a TV for 6 hours.