Prior to the October 1987 stock market crash, the P/E ratio for the S&P 500 was above 20, but in recent years, the ratio has averaged higher.

在1987年10月的股灾(October19 Black Monday)爆发之前，标准普尔500的市盈率保持在20以上。

youdao

Very large coronal mass ejections are thought to happen every 500 years or so (the most recent was in 1859).

大规模的日冕物质抛射被认为每隔500年或约500年发生一次（最近一次发生于1859年）。

youdao

'Warren Buffett believes in this rule as well,' he added, referring to Mr. Buffett's bullish selling of long-term put options on the Standard & Poor's 500-stock index in recent years.

他说，巴菲特(Warren Buffett)也相信这一准则。 由于看涨股市前景，巴菲特近年来持续抛售标准普尔500股指期货的长期看跌期权。

youdao

The Fortune 500 list in recent years ranks it under the Information Technology Services industry, when years ago it would have been ranked under Computers, Office Equipment.

FORBES: Thinking Ourselves Forward

Facebook has grown explosively in recent years, and has about 500 million users globally.

WSJ: Man Claims Ownership of Facebook

In a recent paper in Ecosystems, Robert Steneck and his colleagues at the University of Maine report that 4, 500 years of archaeological data from village middens along the coast, and also more recent fishing records, suggest that fishing pressures may have pushed the ecosystem of the Gulf of Maine into a new, less-stable state.

ECONOMIST: Lobsters in Maine