Which of the following statements is true?

a : wind is the most commonly used renewable energy source in the united states.
b : hydropower uses the kinetic energy of water to generate electricity.
c : wind energy does not use a turbine or a generator to produce electricity.
d : solar energy can only be used on earth. it can't be used in space.

Awell-diversified portfolio needs about 20-25 stocks from different categories is this true or false?

Acomputer has a two-level cache. suppose that 60% of the memory references hit on the first level cache, 35% hit on the second level, and 5% miss. the access times are 5 nsec, 15 nsec, and 60 nsec, respectively, where the times for the level 2 cache and memory start counting at the moment it is known that they are needed (e.g., a level 2 cache access does not even start until the level 1 cache miss occurs). what is the average access time?

What is the difference between the internet and the world wide web?