用适当的介词填空
(1)He was born____ a cold morning.
(2)The girl began to learn to play the piano____ an early age.
(3)The beautiful music was____ Gu Jianfen.
(4)We often watch concerts____ TV.
(5)The boy can play all types____ instruments(乐器).
①生产力水平提高
②内燃机的广泛应用促进石油产量大增
③汽车等新的交通工具加强了世界各地的联系
④大企业时代到来
化学与社会、生活密切相关,下列说法正确的是( )
绥靖政策达到顶峰的标志是—— ____ 。