How long are you staying? —I’m staying ______ a month.[ ]

Jack’s parents can’t go to the parents’ meeting because they ________ to Beijing on business.

I find ________ difficult to remember everything, though I’m still young.

Xinjiang is one of the largest autonomous regions in China. It’s _____ the northwest of China. [ ]

Do you know the woman called Yu Dan?—-Yes. She is regarded _______ one of the best speakers in our country.