How many justices serve at one time on the Supreme Court?

The online retailer Amazon must collect sales taxes on items Texas consumers purchase because

A) ?it has facilities in the state of Texas. B) ?it uses the Internet for consumer purchases. C) ?Texas is a member of the Streamlined Sales and Use Tax Governing Board. D) ?the Texas Supreme Court has ordered it to do so.

Under the system created by the Framers, the national and state governments share power and derive all authority from __________

a. the Bill of Rights b. the Constitution c. the people d. the president