When an aluminum rivet is upset against a softer material, a washer must be used under the upsethead to prevent eruption of the softer material.
当一个铝铆钉的镦头形成在较软的材料一边时，必需在铆钉镦头下使用垫片以防止较软材料胀裂。
2
Don't be upset because opportunity comes in different ways and if your head is down, you might not see it.
不要沮丧，因为机会以不同的方式出现，如果你低下头，就可能看不到它。
3
Inherited diseases, brain disorders associated with mental illness, and head injuries can all affect the way the brain works and upset the daily activities of the rest of the body.