TASK DEFINITION: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
PROBLEM: From what era, once thought devoid of animal life, was evidence of grazer populations discovered?, Context: Some paleontologists suggest that animals appeared much earlier than the Cambrian explosion, possibly as early as 1 billion years ago. Trace fossils such as tracks and burrows found in the Tonian period indicate the presence of triploblastic worms, like metazoans, roughly as large (about 5 mm wide) and complex as earthworms. During the beginning of the Tonian period around 1 billion years ago, there was a decrease in Stromatolite diversity, which may indicate the appearance of grazing animals, since stromatolite diversity increased when grazing animals went extinct at the End Permian and End Ordovician extinction events, and decreased shortly after the grazer populations recovered. However the discovery that tracks very similar to these early trace fossils are produced today by the giant single-celled protist Gromia sphaerica casts doubt on their interpretation as evidence of early animal evolution.

SOLUTION: the Tonian period

PROBLEM: What is the Crown Liquor saloon?, Context: CAMRA maintains a "National Inventory" of historical notability and of architecturally and decoratively notable pubs. The National Trust owns thirty-six public houses of historic interest including the George Inn, Southwark, London and The Crown Liquor Saloon, Belfast, Northern Ireland.

SOLUTION: public houses

PROBLEM: What lasted for a number of years?, Context: The top ten (eleven in season ten) toured at the end of every season. In the season twelve tour a semi-finalist who won a sing-off was also added to the tour. Kellogg's Pop-Tarts was the sponsor for the first seven seasons, and Guitar Hero was added for the season seven tour. M&M's Pretzel Chocolate Candies was a sponsor of the season nine tour. The season five tour was the most successful tour with gross of over $35 million.

SOLUTION:
Kellogg's Pop-Tarts was the sponsor for the first seven seasons