question: in the diagram d is the diameter of the circle, a is the length of the arc ab and x is the length of nb which guo wanted to calculate.
Capitalize this past sentence correctly.
A: In the diagram d is the diameter of the circle, a is the length of the arc AB and x is the length of NB which Guo wanted to calculate.

question: today there aren't many traces left of the quiet, modest girl who didn't dare to voice her own opinions.
Capitalize this past sentence correctly.
A: Today there aren't many traces left of the quiet, modest girl who didn't dare to voice her own opinions.

question: class 1 functions were those functions which were the limit of a sequence of continuous functions.
Capitalize this past sentence correctly.
A: Class 1 functions were those functions which were the limit of a sequence of continuous functions.