This Thursday, May 8, we are happy to have youalong for CNN STUDENT NEWS. I'm Carl Azuz. Youmight not have heard of synthetic drugs. This candescribe a wide range of chemical substances thatmimic the effects of other drugs like marijuana orheroine. The U.S. government says syntheticdrugs can be even more dangerous than the illegalones they try to imitate. Synthetic ingredients aresometimes more potent. They are untested. The names in ingredients are often changed toprevent drug busts, but that doesn't always work. Yesterday, the government announcedmore than 150 people have been arrested over the past four months for making or sellingsynthetic drugs. Police seized hundreds of thousands of drug packages and more than 20million in cash and other assets.

The government's particularly concerned about synthetic drugs in part because a 2012survey found that one in nine high school seniors said they used synthetic marijuana. Thatwas that group's second most frequently used drug behind actual marijuana.

Next up today, Janet Yellen, she's the leader of the Federal Reserve, the Central Bank of theU.S. She expects the U.S. economy to grow "somewhat faster than it did last year. But she hassome concerns. For one, the U.S. housing market. It's weak, homes are at selling as well aseconomists expected. One thing the Fed's doing is keeping interest rates low to encouragepeople to borrow money for purchases like houses.

Interest rates are one tool at the Fed's disposal.

So, we've had that phase that, you know, money makes the world go around, but you mayhave asked yourself once or twice, OK, well, who makes the money go around? So, the answeris the Federal Reserve or as my friends and I like to call it, the Fed.

So, the Fed is pretty much unlike any other U.S. institution that I can think of.

It's run by board of governors based in Washington D.C., it has 12 banks located around themain banking centers of the country, some places like New York, San Francisco, Philadelphia.

Presidents of these banks and the board of governors, they meet eight times a year to makebig policy decisions and to ensure the economy is moving at a stable quick.