It was Jack’s 16th birthday yesterday. Why didn’t you go to his party— Oh, I________.

ing renewable energy is a simpleidea, but ______ we find it hard to put into practice

-year-old woman, who died of respiratoryfailure on Dec 6, was confirmed to have been carrying ____H10N8 virus

It is said that by no means _____to get into this laboratory without Mr. Jackson’s permission. [ ]

______ the serious sandstorms that have hit the city recently, the quality of the air in Beijing is very poor[ ]