Please answer this: Question: "When did the Aves class begin?"  Context: "The fossil record indicates that birds are the last surviving dinosaurs, having evolved from feathered ancestors within the theropod group of saurischian dinosaurs. True birds first appeared during the Cretaceous period, around 100 million years ago. DNA-based evidence finds that birds diversified dramatically around the time of the Cretaceous–Paleogene extinction event that killed off all other dinosaurs. Birds in South America survived this event and then migrated to other parts of the world via multiple land bridges while diversifying during periods of global cooling. Primitive bird-like dinosaurs that lie outside class Aves proper, in the broader group Avialae, have been found dating back to the mid-Jurassic period. Many of these early "stem-birds", such as Archaeopteryx, were not yet capable of fully powered flight, and many retained primitive characteristics like toothy jaws in place of beaks, and long bony tails."  Answer:
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Answer: the Cretaceous


Please answer this: Question: "What was an issue with not having AI?"  Context: "Airborne Interception radar (AI) was unreliable. The heavy fighting in the Battle of Britain had eaten up most of Fighter Command's resources, so there was little investment in night fighting. Bombers were flown with airborne search lights out of desperation[citation needed], but to little avail. Of greater potential was the GL (Gunlaying) radar and searchlights with fighter direction from RAF fighter control rooms to begin a GCI system (Ground Control-led Interception) under Group-level control (No. 10 Group RAF, No. 11 Group RAF and No. 12 Group RAF)."  Answer:
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Answer: Bombers were flown with airborne search lights out of desperation


Please answer this: Question: "What could be said about unicellular organisms with a nucleus?"  Context: "Whereas the chromosomes of prokaryotes are relatively gene-dense, those of eukaryotes often contain regions of DNA that serve no obvious function. Simple single-celled eukaryotes have relatively small amounts of such DNA, whereas the genomes of complex multicellular organisms, including humans, contain an absolute majority of DNA without an identified function. This DNA has often been referred to as "junk DNA". However, more recent analyses suggest that, although protein-coding DNA makes up barely 2% of the human genome, about 80% of the bases in the genome may be expressed, so the term "junk DNA" may be a misnomer."  Answer:
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Answer: