Practice with how much pressure needs to be put on the razor or if the thumb should hold hair against the razor's edge are each part of experimenting with this type of thinning out of hair.
这种方法需要反复练习，来摸准把头发按向刀刃的大拇指需要用多大力。
2
Old rules ofthumb which said that countries should keep enough reserves to cover only short-term foreign debt now look hopelessly outof date.
过去粗浅的经验——国家应该维持足够的外汇储备来应付仅仅是短期的外债——现在看来绝望又过时。
3
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.