1)¿Cuáles son los sentidos comunes que se pueden utilizar, para identificar un metal, gases o líquido?

The question is another language. Translation in English language is as following:

What are the common sensors that can be used to identify metal, gas or liquid?

Common sensors that can be used to identify metal, gas or liquid are as following:

the product of the pressure and volume is also constant

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them