My PI helps to modify my thesis. He keeps changing the degree mark '°' to '0' as the superscript in a degree centigrade mark. He also changes every 'in the phase' to 'at the phase'.
As I searched, superscript 0 was used when initially creating the degree mark. But now ° is used in all the degree mark. 'Phase' means a period of time and in most paper and textbooks, people use 'in the phase'.
I'm confused about these changes. Is the '°' wrong, or 'in the phase' wrong? What do you use in the paper/thesis writing?
An example of using '°' and 'phase' in my thesis: 'The cells cultured at 30 °C for 3 days were in the stationary phase.' 'Stationary phase' is one of the cell-growth phases that range from several hours to several days.
Thanks to @Houska for your vision and practical suggestions <3
Thanks to @AndreasRejbrand for correcting the degree sign to be 'U+00B0: DEGREE SIGN'. I have changed the sign in the title and body. In my PI's comments, he highlighted my degree sign (that I added through 'Symbols' in MS Word) and commented 'Should be a zero in superscript! Change all the rest.' So I believe he means using a zero.
PS. My PI is a Chinese who has been working in the UK for 20 years. His spoken English is fine, but sometimes he mixes up "she" and "he", or forgets to add 's' in a verb with the third person.