Say when you're at the front of C prime, your thumb points to the right, your index points up because that's where the surface is, and then your middle finger will point out.
你在曲线C的前端，你的拇指指向右边，你给指出来了，因为那就是这个表面所在，然后你的中指就会指出。
2
I know the index-card waltz of (auto)biographies, poems and novels you are dancing: those same names are still so close to the surface of my mind nearly four decades later.