Good morning, boys and girls. Here is____school news on TV. An international group is visiting our school this____. There are____teachers and two students in the group. Look!____is Mr White and he is from the UK. The woman near____is Miss Green. She is from France. The____man talking with our students is Mr Brown and he____from Canada. The beautiful girl is from Japan.____name is Judy. Look____that boy. He looks shy. Is he a Japanese, too?____, he is from Chinatown in New York. He is an overseas Chinese!

“噬菌体侵染细菌的实验”是研究遗传物质的经典实验，主要过程如下：①标记噬菌体→②噬菌体与细菌混合培养→③搅拌、离心→④检测放射性．下列叙述正确的是（　　）