No, James Cook did not discover Alaska. He is known for his explorations of the Pacific, including the coasts of North America, but Alaska had been inhabited by Indigenous peoples long before Cook's arrival. Cook's voyages in the late 18th century helped chart parts of the Alaskan coastline, but he was not the first to "discover" the region.
James Cook did not discover New Guinea.
Heading for Alaska, Cook sailed to and named the Christmas Islands (arriving on December 25, 1777, hence the name).
no
James cook
James Cook was the first to chart the east coast of Australia.
Yes, James Cook is generally credited with the dicovery of Hawaii.
James Cook charted the east coast of Australia.
Captain James Cook
James Cook did not discover lemon juice but he used it, together with lime juice, to help ward off scurvy in his crew.
James Cook did not discover any countries. He first arrived in New Zealand, but Abel Tasman had discovered the islands in 1642.
sanfrancisco
1770