A:蒸汽机的发明
B:发电机的问世
C:有轨电车的创制
D:内燃机的广泛应用
增大物体的____ ,降低物体的____ ,有助于提高物体的稳定程度.
某同学为了探究废弃塑料薄膜混杂在土壤中对植物生长的影响.设计了如下实验:取两个同样的花盆,找5﹣8个废旧塑料袋,剪成小碎片,再取约4kg的腐殖质,分为两等份,一份直接装入花盆中,另一份与塑料碎片混匀后,装入另一花盆中,将两株生长状况相同的同种花草分别栽到两个花盆中,在同样条件下(温度、浇水、光照等)让其生长6﹣8个月后观察二者的生长状况.
“欧洲人说,他发现了新大陆,把欧洲文明传到美洲,是一个有功之臣;印第安人说,他把欧洲强盗带到了美洲,掠夺我们的财富,是一个恶魔。”这里的“他”是( )
在初中即将毕业之际, 请你以张明的名义给英国笔友Brian写一封感谢信, 要点提示如下:
three years ago
a new comer, have no friends and feel lonely…..
During three years
Brain have written many letters to help you in different ways:
Encourage you to make more friends.
Tell you the ways how to learn English well
…….
You have changed a lot, for example, ……..
invite him to come to Hangzhou to pay a visit…….
要求:
①词数:80--100个
②信的开头和结尾已给出, 不计入总词数
③要点齐全, 行文连贯, 可适当发挥
Dear Brian,
How time flies! We have been friends for three years. I'm writing to thank you for your help!
Three years ago, ……
Hope to see you soon!
Yours,
Zhang Ming