explain why testing can only detect the presence of errors, not their absence.

Explanation: Testing is a set of activities that aim to detect software anomalies in a way that the errors can be discovered and correctes. The goal of software testing is to observe if the software behavior meet the requirements that they are expected to meet. Testing demonstrates to the developer that the software fullfils its requirements and it is a way to find out if it behaves in a incorrect, undesirable ou different form from the specifications.

we can all learn from our past mistakes because we all have different ways of learning different types of techniques. my way may or may not another classmate remember and have the repetition to acknowledge such standard. such as remembering acronyms. using abbreviations to us remember keep things in order in our memory. this us figure out what comes next in the sequence. if so, what we have is a sentence of just letters all in caps. we either know the meaning or have no idea what it stands for. most of the time we know the meaning and context. but most of us who don't know, should learn by having a quick glance at what needs to be remembered. such as repetition in the memory for acronyms. one way that me, is the fact that i'm always doing math and english assignments. so we have to remember specific meanings such as soapstone for documents, such as citing correctly. or pemdas for doing the equations correctly, even if it's the super long way. this works for everyone. you just have to find what works for you by practicing and repetition daily.