___ the safety of gas, the government has checked the city’s gas supply system thoroughly. [ ]

What a long queue!— Yeah．We ________________ up in the past few hours for tickets back home

you have told him the answer had itbeen possible—I would have, but I ______so busy then

How often do you see your grandparents—_______.

Someone wants you on the phone．-________nobody knows I am here.[ ]