Mark the true statement(s) concerning memory. It is possible for memories in long-term memory (LTM) to remain there for a lifetime. Short-term memory keeps information for about 30 minutes. The ability to retrieve knowledge depends on frequency and recency. Acoustic memory is one of the three basic types of short-term memory. Memory does not apply to psychomotor skills. Information passes from STM to LTM when it has some significance attached to it. LTM is a pure recall of information or events.