Ca3(PO4)2+SiO2+C →高温 CaSiO3+P4↑+CO↑
1947年,英国被迫同意印度独立,翻开了印度历史新的一页。( )
读图“澳大利亚养羊业在世界上的地位图”,完成下题。
甲、乙两台机床同时加工直径为10mm的同种规格零件,为了检查两台机床加工零件的稳定性,质检员从两台机床的产品中各抽取5件进行检测,结果如下(单位:mm):
甲
10
9.8
10.2
乙
9.9
10.1
(1)分别求出这两台机床所加工零件直径的平均数和方差;
(2)根据所学的统计知识,你认为哪一台机床生产零件的稳定性更好一些,说明理由.
This is Jim. He is thirteen. He is from the USA. He is a student. He has a good friend. His name is Jack. Jack is fifteen. He is from Canada. Jack is tall but Jim is short. They are in the same class, but they are in different grades. Jim is in Class Two. Jack is in Class Two, too. They go to school(上学) at seven in the morning and go home(回家) at six in the afternoon.