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）：
play a …role (in) because of come up
such as even if play a …part (in)
|
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.
，则sin2θ=
高温下，超氧化钾晶体呈立方体结构．晶体中氧的化合价部分为0价，部分为-2价．如图为超氧化钾晶体的一个晶胞（晶体中最小的重复单元）．则下列说法正确的是（ ）
