车轮上标记可采用（）等方式生成。
A.热压、冷打和铸造
B.热压、冷打、锻造
C.热压、铸造、锻造
D.冷打、锻造、铸造
参考答案：A
—Hey ,it’s you, Jackie! I didn’t think you could be here．
—A big surprise ,right? I _______ for you all the afternoon．
A．have waited
B．was waiting
C．have been waiting
D．waited
沙地土壤中粘粒含量与沙地土壤肥力有何关系？为什么？
