预防子宫脱垂最主要的措施是

A．积极开展计划生育

B．推行科学接生和作好产褥期保健

C．防治慢性气管炎和便秘

D．对老年人适当补充雌激素

E．加强营养，增强体质

— Do you often go swimming_____ Sunday mornings?

— Yes. Why not _____with me this Sunday?

A．on, go

B．in; to go

C．on; going

D．in going