美国有线新闻 CNN 特朗普炒掉国务卿蒂勒森 前往加州视察边境墙（在线收听）

We're starting to look at the U.S. secretary of state. This is the top adviser to the president on international affairs. He or she conveys U.S. foreign policy to the rest of the world. The person who's held the job since last February is Rex Tillerson. He's a former businessman who used to lead the ExxonMobil oil and gas company, as well as the Boy Scouts of America.

And some observers say Tillerson tackled the secretary of state job with the same diligence and dedication he used to lead the Boy Scouts from 2010 to 2012. But critics say that Tillerson's business experience did not translate to effective leadership at the State Department. And on several issues, like international trade and government policy, related to Iran, North Korea, and Russia, Secretary Tillerson often disagreed with President Donald Trump.

Yesterday, the president announced that he was firing the secretary of state, saying the two of them were not really thinking the same.

President Trump said he and Mike Pompeo have a similar thought process. Pompeo is the director of the Central Intelligence Agency and he's now President Trump's choice to become the next secretary of state.

Pompeo graduated first in his class at the U.S. Military Academy at West Point and later from Harvard Law School. The Republican from Kansas served three terms in the U.S. House of Representatives before he became CIA director. But like that job, the position of secretary of state is cabinet level. So, Director Pompeo will need approval from the Senate to fill it. His confirmation hearings are set for April.

A border measuring 1,954 miles separates what two countries?

North Korea and South Korea, U.S. and Canada, U.S. and Mexico, or China and Russia?

This is the length of the border between the U.S. and its southern neighbor, Mexico.

AZUZ: Yesterday, President Trump had a look at prototypes for the wall he wants built on that border. One of his first promises as presidential candidate was to build the wall and have the nation of Mexico pay for it. That country has refused, but the Trump administration says it will eventually find a way to have Mexico fund the wall. For now, it needs money from Congress.

Estimates for building the wall ranged from $10 billion to $70 billion. The president says walls work to keep illegal immigrants out of the country. Critics say borders can be secured more cheaply with fencing, border agents and technology.

The eight prototypes the president saw yesterday in San Diego, California, had been standing and tested since October.