①高温灭菌 ②配制培养基 ③将接种后的培养基放在适宜的温度下培养 ④接种
A:①④③②
B:②④③①
C:③①②④
D:②①④③
如东某同学准备在中秋、国庆双节期间去美国自助游,下图为他在“去哪儿网”预定机票的信息(起降时间为当地时间)。该同学在美国旅游期间( )
属于氧化物的是( )
They lost their way in the forest, and ___ made matters worse was that night began to fall.