根据听到的内容回答下列问题:
What kind of proof did the man probably have when he bought the radio?
A.A receipt and the cheque stub. B.rnle guarantee and the receipt. C.The radio and the box. D.The credit card and a receipt.
参考答案:
答案解析:
关于工业炸药的基本要求,说法正确的是( )。
关于工业炸药的基本要求,说法正确的是( )。 A.有足够的威力以满足各种矿岩的爆破要求 B.有较高的机械感度和适度的起爆感度 C.炸药的配比满足正氧平衡条件 D