为减少校车事故的发生,我市今年计划投资35亿为全市部分中小学生购买新校车,把35亿用科学记数法表示,应为( )。
3.5×109
Having longed so much to have a look at the famous star, the fans looked forward anxiously ____ the live concert. [ ]
A. not to missing
B. to not miss
C. not to miss
D. to not missing
矿井空气中的主要成份有()、()、()。