患者，女，22岁。经期腹痛，始于行经初期，经量少，色紫暗，2天后经量增多，腹痛略减，伴少腹冷，四肢不温，舌苔白润，脉沉紧。诊断为痛经。 患者服药时间宜在（）

A.疼痛时服用，痛止停服

B.月经前3～5日开始用药，痛止停服

C.月经开始时服用，痛止停服

D.月经开始后3～5日开始用药，痛止停服

E.从月经开始服药至月经结束

How is the external flotation bladder of an immersion suit inflated?（）

A.It is inflated by a small CO₂ bottle that is automatically tripped when the front zipper is at the top of the zipper track

B.It is inflated by a small CO₂ bottle that is manually tripped

C.It is inflated by blowing through an inflation tube

D.It inflates by seawater bleeding into the inflation bladder and reacting with a chemical