Is it common to see frost during some college commencements?
College commencement ceremonies often happen during the months of December, May, and sometimes June. Frost isn't uncommon to see during the month of December, as it is the winter.
The answer is yes.

Is Bern a poor choice for a xenophobic Swiss citizen to live?
Xenophobic people do not like people from other countries, such as tourists. Bern Switzerland was once described by CNN as being a relatively tourist free area. Zurich and Geneva get the most tourist traffic out of any city in Switzerland.
The answer is no.

Is the CIA part of the Department of Defense?
The Department of Defense covers national defense and the armed forces, led by the Secretary of Defense. The CIA is a federal agency within the United States Intelligence Community, which answers to the Director of National Intelligence.
The answer is no.

Did H.G. Wells' "War of the Worlds" include cosmic rays?
The book "War of the Worlds" was published in 1898. Cosmic rays were not discovered until 1912.
The answer is no.