Before revision:  Our algorithm first reads off-line the corpus to generate collections of all answerable questions associated with their answers, and then queries the pre-constructed question spaces online to find answers that are most likely to be asked in the given way.
After revision:  Our algorithm first reads off-line the corpus to generate collections of all answerable questions associated with their answers, and then uses an online retriever to respond to user queries by searching the pre-constructed question spaces online to find answers that are most likely to be asked in the given way.