在经历两年停机维护、加固升级及数月重启准备后,世界最大的粒子加速器—欧洲大型强子对撞机于2015年4月5日正式开启第二阶段运行。它通过超导磁铁加速并碰撞粒子,可在微观尺度上还原宇宙大爆炸后的宇宙初期形态,帮助科学家研究宇宙起源并寻找新粒子。这表明①人们对客观事物的认识总要受到具体的实践水平的限制②认识工具的日益完备成为实践不断向前发展的动力③在认识到实践的多次反复中能发现和发展真理④世界的真正统一性就在于它的物质性
Lately some scientists are experimenting ___________ white mice to ____________ this kind of medicine.
When the reached the top of the hill ,they _______________ so they had to stop for a rest.
John ____________ his students is playing basketball on the playground.
He does ___________________ that he cannot spare no time to play with his children.
.He has __________________ the surroundings & now he is getting well on with his classmates;______________,he is treated as a normal student in the school.