用钢板或钢带卷成筒形后焊接而成的（），多用在低温、低压和不重要的地方。
A、无缝钢管
B、铸铁管
C、焊接管
D、聚丙烯（PP）管
参考答案：C
补全对话。
Kevin: So, Tina, what 1______ did you do?
Tina: You won't believe it, but I met Jake Dean!
Kevin: Jack Dean, the famous actor? You really 2______ him?
Tina: Yes! He is making 3______ movie at the aquarium.
Kevin: Wow. Did you get his autograph?
Tina: 4______, I didn't. Laura did. But I took his photo. 5______ it is.
Kevin: Wow. 6______ there other actors there?
Tina: No. We 7______ saw Jake. Look, here's Toby. He 8______ a prize in the 9______ Shop.
Kevin: Did you win that hat?
Tina: No, I didn't. I bought 10______.
零售，含脱脂奶粉、豆粉、酵母、维生素等添加物的婴幼儿食用奶粉
