Just before your method, your medical professional will question you on your consent to utilize nitrous oxide. Following that, a plastic mask is going to be placed around your mouth and nose. The laughing fuel flows through the mask and also you breathe it in.Bài 7: Xu h??ng bi?n ??i thành ph?n và m?t s? tính ch?t c?a h?p ch?t trong m?t chu kì