土壤剖面构造
参考答案：
土壤剖面构造就是指土壤剖面从上到下不同土层的排列方式。
不等式2x+9≥3（x+2）的正整数解是______．
补全对话。
A: Can you speak English?
B: Sorry, I can't.
A: 1 ?
B: I want to join the English club and the chess club.
A: Can you play chess?
B: Yes, but 2 . 3 ?
A: I can play it well, but I can't sing well, so 4 .
B: I want to learn to sing. I think 5 .
