Tourism to sites of cultural and natural significance has existed at least since the time of Greek Antiquity, as reflected by Hellenistic world's invention of the Seven Wonders of the World. please tell me the part of speech of the word "as".

REUTERS REPORT------- A sign in a landmark Philadelphia restaurant asking customers to order in English is sparking controversy in the metropolis known as the "City of Brotherly Love." The owner of Geno's Steaks said on Thursday that the sign,

He is a rude man who mixes difficultly and uncomfortably with other people. ---------------------------------------------------------------------- Is it correct?

without further endangering chimps ＝without endangering chimps? I can't imagine that the tests could develop without any endangerment.

This study does not further endanger chimp populations, does it?

The scientists believe that the virus spread from chimps to humans most likely through bushmeat hunters. Developing the tests to do this study without further endangering chimp populations took seven years. Science magazine published the findings.

why is "expand on the base of" wrong?

He said that they had worked on the project for 10 years and Tom could expand it on the base of their work . --------------- I don't understand "expand it on the base of their work".

Does "without the aid of a parachute" mean the rate of sagging downwards is very quick?

Just when you think you have the experience, the style, the wisdom, the confidence to be gorgeous, it turns out your body parts are descending without the aid of a parachute and going up a light of stairs without gasping is a major fitness