A:某市的4个区共有2000名学生,且4个区的学生人数之比为3: 2 :8 :2,从中抽取200人入样
B:从某厂生产的2000个电子元件中随机抽取5个入样
C:从某厂生产的2000个电子元件中随机抽取200个入样
D:从某厂生产的20个电子元件中随机抽取5个入样
从方框中选择最佳选项补全对话,其中有两项多余。
A: What are you doing?B: I’m reading a letter from my pen pal.A: ____B: A girl.A: Where is she from?B: ____ A: What does she look like?B:____ A: Is she tall?B: ____ . She is of medium height. A: Look at her photo.B: Oh. She’s good-looking and a little thin. Can she speak Chinese? A: ____
能正确表示一条食物链的是( )
作家作品常识表述正确的一项是( )。