A:钟乳石、生石花都是非生物
B:“人间四月芳菲尽,山寺桃花始盛开”体现了环境因素对生物的影响
C:某同学在显微镜下观察细胞结构时,没有看到叶绿体,由此判断它不是植物细胞
D:绿色植物光合作用可制造氧气,所以室内应多放栽培的绿色植物,这有利于改善室内空气质量
把分式xyx-3y中的x和y都扩大2倍,分式的值( )
—Where are you going for your winter holiday?
—I’m going to visit Kunming. It is ______ too hot _______ too cold.
We watched, amazed as fire ____(爆发) on the outside of the spaceship.