To what did the ancient Greek historian Thucydides attribute the independence of the poleis?

In a typical late-medieval tempera painting, the frame is not integral in the painting process and is added later

True or False

What strategy helped Alfred Stieglitz promote photography as a legitimate art form in the early twentieth century?

a)  He included essays on modern art in Camera Work. b)  He exhibited his photographs at the Museum of Modern Art. c)  He made portraits of famous actors and actresses. d)  He manipulated his photographs to imitate popular styles in painting.