A:图中①②属于真核生物,③④属于原核生物
B:人们酿酒、做面包离不开②
C:图③有细胞壁、细胞膜,却没有成形的细胞核
D:④所示生物只能寄生在活细胞中
下列有关文学常识和名著阅读的表述,有错误的一项是( )
西气东输工程能使本地的天然气资源得到大规模开发,请你谈谈西气东输工程的实施对西部地区发展的好处。
I am an English girl. My name is Mary. I'm twelve. My dad and mom are English teachers. I have a brother. His name is Tom and he is thirteen years old. We are in China now. We are in Beijing No. 4 Junior High School. Tom is in Class 4, Grade 7 and I am in Class 9, Grade 7. I have a dog. My dog looks strong. It has a big mouth and two big black ears. We have many Chinese friends here. They are good.
某同学为测一物体质量,找到一个力电转换器,该转换器的输出电压正比于受压面的压力,如图,测量时先调节输入电压,使转换器空载时输出电压为0,而后在其上放一物体,即可测得物体质量 成正比的输出电压.该力电转换器中的主元件是 ____(选填A光敏材料 B热敏材料 C压敏材料),该装置在称量物体质量时,要水平放置,理由是 ____