[单项选择]跟单员进行原材料采购跟单的中心任务是( )。
A. 交货时间
B. 交货价格
C. 交货地点
D. 交货数量

Darkness approached and a cold, angry wind gnawed at the tent like a mad dog. Camped above treeline in the Wind River Mountains of Wyoming, the torrents of air were not unexpected and only a minor disturbance compared to the bestial gnawing going on behind my belly button. In an attempt to limit exposure of my bare bottom to the ice-toothed storm, I had pre-dug a haft dozen catholes within dashing distance. Over and over, through the long night, the same scenario was repeated: out of the bay, out of the tent, rush, squat, rush back. "Everyone can master a grief," wrote Shakespeare, "but he that has it."
Diarrhea, the modem word, resembles the old Greek expression for "a flowing through." Ancient Egyptian doctors left descriptions of the suffering of Pharaohs scratched on papyrus even before Hippocrates, the old Greek, gave it a name few people can spell correctly. An equal opportunity affliction, diarrhea has laid low kings and common men, wo
A. withstanding the coldness
B. Camping in the mountains
C. Getting up repeatedly at night
D. Reading Shakespeare in bed

Music is often divided into several categories or groups. Some of the categories are: classical music, traditional music, rock music, and jazz music.
The first kind, classical music, refers to orchestra music that originated in Europe a few hundred years ago. Most of the original classical music was composed, or written, in Italy, Germany, Austria, or Russia. Beethoven and Bach were two famous composers of classical music. Classical music is usually played by a variety of string instruments, such as the violin, and by a variety of wind instruments, such as the flute.
The second type of music is traditional music. Traditional music is music that comes from a particular culture. Every culture has its own special forms of traditional music. For example, "blues" music is one kind of traditional music in the United States and "enka" music is one kind of traditional music in Japan. Each culture has its own traditional music, and its own special instr
A. Electric instruments.
B. Chemical instruments.
C. Medical instruments.
D. Probing instruments.