1) You meant Tringapore. It's simply explained in one of polandball's oldest meme

Singaporeball dad: Get mole As ol I send yuo to wolk for nike in China !
Singaporeball son: Dad. Yuo arways want As so much I wirr tuln into one . Hgnnn... POP ! <Turns to Triangle>
Singappreball dad: This is of no A, is just oldinaly Derta, I send yuo to China
Tringapore son: Aiya <Suddenly in NIKE factory>
PRCChinaball: Get backings to wolk !

Tringapore's weird triangle shape makes it hard for larger countries to squash it as the tip is very pointy (Small island, stronk military) & is very stoic, even enough to kill the Reichtangle in this meme:

Germany: Hello Singapur (Face looks happy)
Tringapore: Huh ? <confused face> Why yuo here ?
Reichtangle: Surprise Anschluss
Tringapore: How yuo is of stand ?
Reichtangle: Uh... Schißße <wind blows him down>
Tringapore: Yuo can into 2D ? <Really confused and shocked>
Tringapore, <Reichtangle falls and dies by being stabbed by the sharp point of Tringapore> Help lah !

Ryycia: I think I answered enough questions about countries, can you please stop taxing my brain and gimme something else please ? I will give you your answers shortly but please take a break from throwing geography to my face.

Tumen river: The gateway for North Koreans to defect to free(er) PRC china or (sorta moar) freer Russia. Period.

Inner Mongolia: Autonomous region of China south to Mongolia, there is literally NOTHING interesting about the place, its landlocked, dry and a part of the Gobi desert. Only a few nomads serving really ancient chinese food.

Fujian: Yet another province in China with a coast to the South China Sea and it's capital Xiamen has also an extensive history of Europeans colonizing the city as the weak Ming China had to give whites concessions. Mostly famous for mountains with a killer view of the SCS. Go there. I recommend it as the 5th region in China I would like to visit again. (#1is Beijing, if the air improves)