A:混合气体中一定有甲烷
B:混合气体中一定是甲烷和乙烯
C:混合气体中一定有乙烷
D:混合气体中一定有乙炔(CH≡CH)
读拼音,写词语。
jù pà
chǎo cài
guō sháo
diǎn jiǎo
____
Lots of constructive advice has been ____ ____ at the meeting to settle the argument.