You will know how cool it is to achieve your dream ______ your own hard work.

There was something wrongwith my TV set. Can you mend it —Let me see. I think I can _______.

______ do you go shopping, Mary — Twice a week.

We are all curious about what the astronauts have to____ when they try to drink waterwhile standing ontheir heads.[ ]

依次填入下列横线处的关联词语，最恰当的一组是(　　 )当前全国安全工作形势严峻，出现了种种问题，________有多方面的原因，________根本原因在于原有体制的弊端没有消除，有些政府官员安全责任意识不强。________，要尽快扭转这种局面，________通过进一步深化安全改革，________能实现。