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 CretaceousPaleogene 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.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When did true birds first appear?
Ah, so.. Cretaceous period

From 1966, Witness publications and convention talks built anticipation of the possibility that Christ's thousand-year reign might begin in late 1975 or shortly thereafter. The number of baptisms increased significantly, from about 59,000 in 1966 to more than 297,000 in 1974. By 1975, the number of active members exceeded two million. Membership declined during the late 1970s after expectations for 1975 were proved wrong. Watch Tower Society literature did not state dogmatically that 1975 would definitely mark the end, but in 1980 the Watch Tower Society admitted its responsibility in building up hope regarding that year.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What was one of the major changes that occurred in 1975?
Ah, so.. unanswerable

The traditional buildings of Tuvalu used plants and trees from the native broadleaf forest, including timber from: Pouka, (Hernandia peltata); Ngia or Ingia bush, (Pemphis acidula); Miro, (Thespesia populnea); Tonga, (Rhizophora mucronata); Fau or Fo fafini, or woman's fibre tree (Hibiscus tiliaceus). and fibre from: coconut; Ferra, native fig (Ficus aspem); Fala, screw pine or Pandanus. The buildings were constructed without nails and were lashed and tied together with a plaited sennit rope that was handmade from dried coconut fibre.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What were the traditional building materials on Tuvalu?
Ah, so..
plants and trees