BUKHANNON, West Virginia~~Two rescue teams slowly moved along a two—mile path on Monday night to the site of a coal mine explosion that trapped 13 miners, who had not been heard from since the early morning accident.
Meanwhile, at a nearby church, more than 250 family members and friends gathered, waiting for updates on the rescuers' progress.
The miners were trapped at about .6:30 and many families weren't informed of the accident until about 10 a.m.~~more than three hours after it happened. "It's very upsetting, but you've got to be patient, I guess," said John Helms, whose brother, Terry, was trapped in the mine.
The trapped miners were about 260 fee underground and about 10,000 feet from the Sago Mine's entrance, said Roger Nicholson, a lawyer from International Coal Group.
At a late night news conference, Nicholson said one team had advanced about 4, 800 feet in the four hours since entering the mine just before 6 p.m. Another team entered the mine about 30 minutes later.
He said the crew was very experienced, with some members having worked underground for 30 to 35 years. The miners were equipped with al>out one hour of breathable oxygen each. The company has not released the names of the miners.
The teams test the air about every 500 feet, and have to disconnect the power to the phones they use to communicate with the surface before doing that. "We don't want to be electrifying anything if it's in an atmospfiere with hurnahle gases," Kips said.
The cause of the explosion was not immediately known. High levels of carbon monoxide (一氧化物) were discovered shortly after the explosion, which delayed rescue efforts, but those levels have weakened since then, authorities said.
According to the passage, we ran infer that .
I.    communication with the trapped miners was cut off
J.   the rescue started as soon as the accident happened
K. the two rescue teams entered the mine at the same time
L.  all the miners who were trapped underground were still alive
If the first team advanced at an average speed, they could dig about______per hour.

A．1,000 feet

B．1,200 feet

C．2,400 feet

D．4,800 feet

Where ran the passage he seen?

A．Iii a magazine.

B．In a science hook.

C．On an advertisement.

D．In a newspaper.