This statement is true: <span>The mineral ores for gold and silver are commonly found in the earth's crust.
These two types of metals are known as native metals because they are naturally occurring within the Earth's stratosphere. These metals are usually found through mining processes because they are often found mixed with sediments and other soil components. One method of acquiring gold is called gold panning while silver is obtained mixed with silver sulfide and sulfosalt minerals.</span>
        
             
        
        
        
Answer:
b. complementary proteins
Explanation:
Complementary proteins are proteins that contain all adequate amounts of the essential amino acids when two or more protein sources that are deficient or low in some amino acids are combined together to compensate for the deficiency of the other. The protein sources can be eaten together in a meal or consumed the same day to get a complete protein.
For example, grains are deficient in lysine, while legumes are usually deficient in methionine.  Combination of rice which is a grain, together with beans which is a legume, would give us complementary protein diet, making it a complete protein source with all adequate essential amino acids available.
 
        
             
        
        
        
Explanation:
Policy-makers have two broad types of instruments available for changing consumption and production habits in society. They can use traditional regulatory approaches (sometimes referred to as command-and-control approaches) that set specific standards across polluters, or they can use economic incentive or market-based policies that rely on market forces to correct for producer and consumer behavior. Incentives are extensively discussed in several EPA reports
Two basic types of traditional regulatory approaches exist. The first, a technology or design standard, mandates specific control technologies or production processes that polluters must use to meet an emissions standard. The second, a performance-based standard, also requires that polluters meet an emissions standard, but allows the polluters to choose any available method to meet that standard. Performance-based standards that are technology-based, for example, do not specify a particular technology, but rather consider what available and affordable technologies can achieve when establishing a limit on emissions. At times, EPA may completely ban or phase out the use or production of a particular product or pollutant, as it has done with chlorofluorocarbons (CFCs) and certain pesticides. Regulations can be uniform or can vary according to size of the polluting entity, production processes, or similar factors. Regulations are often tailored in this manner so that similar regulated entities are treated equally. MARK AS BRAINLIEST IF IT HELPS
 
        
             
        
        
        
Answer:
operant conditioning
Explanation:
In operant conditioning, organisms learn to associate events that repeatedly happen together. The word "operant" should be changed to the word "classical." any relatively permanent change in behavior brought about by experience or practice.
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I would say the answer to your question is C) primary succession,because p<span>rimary succession begins on rock formations, such as volcanoes or mountains, or in a place with no organisms or soil. </span>