Please capitalize where necessary: 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.
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.

Q: in a closed system subjected gases of ammonia, hydrogen, methane, and water for electric discharges.

A: In a closed system subjected gases of ammonia, hydrogen, methane, and water for electric discharges.

Q: we accept bookings made with the following credit card companies: american express, visa, visa delta, master card, diners and jcb.
A: We accept bookings made with the following credit card companies: American Express, Visa, Visa Delta, Master Card, Diners and JCB.

Problem: about y430 : blak agate bracelet with extendable chain
Can you repeat this sentence, but capitalize it?
Answer: About Y430 : blak agate bracelet with extendable chain

Text: we proudly offer best price guarantee to our korean jewelry noble and shinning heart shape earrings.this korean jewelry noble and shinning heart shape earrings is offered at the lowest price on the market with premium quality.now it's best chance to make the discount metal earrings deals with bjbead.com.

Correct capitalization: We proudly offer BEST price guarantee to our Korean jewelry noble and shinning heart shape earrings.This Korean jewelry noble and shinning heart shape earrings is offered at the LOWEST price on the market with premium quality.NOW it's best chance to make the discount metal earrings deals with Bjbead.com.

Please capitalize where necessary: you will have one year to report on the knowledge and experience you acquired during the entirety of your project.
A:
You will have one year to report on the knowledge and experience you acquired during the entirety of your project.