Add a letter, take a letter, change a letter: 20 questions

The first five questions are standard general knowledge. The answers to the next five questions are the first five answers (or part thereof) with a letter removed. The next five answers are the first five answers (or part thereof) with a letter added. The final five answers are the first five answers (or part thereof) with a letter changed. In the case of multiple word answers, the same word is modified in each of the groups of five questions. For example, the answer to a question in the first group might be Iron Age. The answer to a question in the second group might then be Ron Atkinson (letter removed), in the third Jeremy Irons (letter added), and in the fourth Tron (letter changed).

Double acrostic authors anagram: 11 questions

If you take the first two letters of each answer, you will have ten groups of two letters. These ten groups of two can be rearranged to form the names of two famous British authors, one primarily a playwright and the other a novelist. The two letter combinations should not be split up when forming the name of the authors.

1. Which author created the detective Jack Frost, as played by David Jason in the series “A Touch of Frost”?
2. By what three initials is the state broadcaster of Ireland commonly known?

Fill in the blank (scientists): 21 questions

Fill in the blanks with the surnames of scientists, astronomers, mathematicians etc.

I was in a shop looking at a bicycle I was thinking of buying. I had taken up cycling after giving up gymnastics. I was very good on the rings, but useless on the pommel horse and a very poor (1).

I asked if it had a (2) but the assistant replied “Sorry, it’s got (3). Are you buying it for yourself?”.
“Yes, it’s (4)”.

Christmas Quiz 2018: 100 questions

Welcome to the Christmas quiz! Please have a crack over Christmas with your friends, family and anyone else you can rope in (because it's probably quite difficult if you tackle it on your own). I'll upload the answers on this site in the New Year. Happy quizzing!