What development led to lisbon portugal becoming the center of the trade world?

Concerns about the environment prompt congress to pass a $1 surcharge tax on each gallon of gasoline. which statement best describes the impact of such a tax

How was the u. s. economy different from european economies following world war 1?

Some organisms have a large geographic range. for example, the norway rat lives on every continent except antarctica. a population of norway rats is the number of rats in one particular area. do you think it’s scientifically possible for a population of norway rats in north america to carry different genetic mutations than a population of norway rats in africa? do you think it’s possible that they carry some of the same mutations? what types of information can scientists learn by studying the genomes of these two populations of rats?