An alloy is a combination of two or more different metals.
合金是兩種以上不同金屬結合而成的。
A combination of internal and external factors caused the company to close down.
內外因結合導致了公司的倒閉。
The two players together make a formidable combination.
這兩個隊員配對兒，難以對付。
She brings to the job a rare combination of youth and experience.
她很年輕，然而干這份工作已有經驗，這是很難得的。
This combination of qualities is generally supposed to be extremely rare.
一般認為，同時具有這樣一些品質極為罕見。