Misc: What was renamed Ho Chi Minh City in 1975?

Questions

What geographic term describes a hill with sharply sloping sides & a flat top?

What insect family has the most varieties, making up 290,000 of the 751,000 insect classes?

What kind of craft was the mast atop the Empire State Building intended to moor?

What kind of seeds can cause drug tests to trigger false positives for opium?

What large fish earned the nickname "cheetah of the sea" for its speed in the water?