2．A small earthquake shook northwest Alaska on Monday．It was the fifth earthquake of the same magnitude（震級） since April in an area with little activity．The magnitude 5.7 quake happened at 4：01am on Monday northeast of the village of Noatak．
Like other earthquakes in the swarm（群），the earthquake was felt in Noatak，a community of 560 people．People there had hardly ever experienced earthquakes and they had some worried residents．Before the swarm that began on April 18th，the last known quake of similar size in the area was a magnitude-5.5 quake in 1981．
The swarm of magnitude-5.7 earthquakes is connected to more than 300 smaller aftershocks．The first earthquake and the others of that magnitude are located in the same area about 20 miles from Noatak．The community is 70 miles north of the Arctic Circle．Monday's earthquake was followed by at least 10 aftershocks．There was no serious property damage or injuries from the earthquakes．
Ruppert，an earthquake expert，said old faults （斷層） had been mapped in the area，but there was still unknown active faults．She said sometimes surface fault scars（斷層痕） could be hidden．"Obviously，since we have all the earthquake activity，there must be some active faults in the area，"Ruppert said．
The series of earthquakes has scientists puzzled about earthquake activity that is considered very unusual in the area．"At this point，we don't really understand the nature of these earthquakes，"Ruppert said．She added that she didn't believe there was any connection between the earthquakes and the Red Dog Mine，located about 35 miles north of Noatak．"All mining activities are very near the surface，"Ruppert said．"But all the earthquakes are miles below the surface．
（1）What can we learn about residents in Noatak in Paragraph 2？
A．They all want to move away．
B．They aren't used to earthquakes．
C．They experienced the biggest earthquake in 1981．
D．They don't believe a big earthquake will come．
（2）We know that Monday's earthquake
．
A．has caused some deaths
B．has caused very bad property damage
C．was followed by 300 aftershocks
D．happened in the north of the Arctic Circle
（3）In Paragraph 4，Ruppert thinks that in the area，
．
A．some active faults exist
B．surface fault scars can be seen
C．a(chǎn)ll the faults have been mapped
D．unknown active faults have been found
（4）According to the last paragraph，we can learn that Ruppert
．
A．is worried about the safety of the Red Dog Mine
B．understands the nature of these earthquakes very well
C．wants to protect the Red Dog Mine from being closed
D．doesn't think the Red Dog Mine caused the earthquakes
（5）What is the passage mainly talking about？
A．Alaska was hit by big earthquakes once again．
B．Active faults were found in northwest Alaska．
C．People in Alaska were worried about earthquakes．
D．A swarm of earthquakes in Alaska made scientists confused．
