What is the "all events test"? Explain briefly. (2%) What is the "immediacy test"? Explain briefly. (2%) What is the "rational basis" test? Explain briefly. (2%) What is the effect of the execution by a taxpayer of a "waiver of the statute of limitations" on his defense of prescription? (2%) What is the basis for the computation of business tax on contractors under the Local Government Code? (2%) How are retiring businesses taxed under the Local Government Code? (2%)