细铁丝在氧气中燃烧,下列现象描述中正确的是( )
A.蓝紫色火焰
B.火花四射
C.淡蓝色火焰
D.冒白烟
细铁丝在氧气中剧烈燃烧,火星四射,放出大量的热,生成一种黑色固体.
故选B.
— Oh, life is so boring!
—Please don’t think so . I suppose you’ve come to the point _______ a change is needed.
A.where
B.when
C.which
D.as
近代人们的社会习俗发生了什么变化?