单项选择题
A．the English language is difficult B．English is difficult C．the English is difficult D．what English is difficult
A．信用证；提单；买方 B．提单；信用证；买方 C．提单；信用证；卖方 D．信用证；提单；卖方
A．plastic drum；gunny bag；wooden case B．wooden ease；plastic drum；gunny bag C．wooden case；gunny bag；plastic drum D．plastic drum；wooden case；gunny bag