把下列短语填入每个句子的空白处（注意所填短语的形式变化）：
1 Dujiangyan(都江堰) is still ___________in irrigation(灌溉) today.
2 That question ___________ at yesterday’s meeting.
3 Karl Marx could speak a few foreign languages, _________Russian and English.
4 You must ask for leave first __________ you have something very important.
5 The media _________ major ________ in influencing people’s opinions.
6 _________ years of hard work she looked like a woman in her fifties.
