A:①②③④
B:②③④
C:①②④
D:①③④
1928年,德国物理学家玻特用α粒子轰击轻金属铍时,发现有一种贯穿能力很强的中性射线.查德威克测出了它的速度不到光速的十分之一,否定了是γ射线的看法,他用这种射线与氢核和氮核分别发生碰撞,求出了这种中性粒子的质量,从而发现了中子.
我和mǔ qīn____坐着小船,到乡下wài zǔ fù____家里去。天下着大雨,雨点打在船蓬上,shā lā____地xiǎng____。船夫披着蓑衣在船后用力地摇着橹。
现有A﹣F六种常见物质,其中B是食品包装中的常用的干燥剂,A、B、C三种白色固体都含有同种金属元素,E是固体单质,D、E、F都含有同种非金属元素,它们的转化关系如图.请回答:
I'm Sally.I have three new teachers.A Chinese teacher,a maths teacher, and an art teacher.My Chinese teacher is Miss Zhang.She's pretty and young.My maths teacher is Mrs Liu.She's tall and thin.My art teacher is Mr Sun.He's tall and strong.He's very kind.
The rabbit ____fish, she ____ carrots. (doesn't like, likes)