Question

more broadly, he became the unofficial curator of cyclotron history and an assiduous chronicler of the spread of the technology, keeping ernest supplied with frequent reports from the field. source: big science. in the sentence above, assiduous has the same or almost the same meaning as: diligent friendly irregular notorious

Explanation:

"Assiduous" means showing great care and perseverance in carrying out tasks. "Diligent" also implies being hard - working and persevering. The other options "friendly", "irregular", and "notorious" do not have similar meanings.

Answer:

A. diligent