JERUSALEM -Israel's Environmental Protection Ministry asked citizens to avoid unnecessary physical activity and stay indoors on Wednesday，as a serious sandstorm struck the Middle East in a thick yellow haze（霾）for a second day with no hope to see things clearly.
   The ministry said heavy levels of dust and sand in the air were threats to cities throughout the country.The ministry's website advised pregnant women，the elderly and those with heart and respiratory（呼吸的）conditions to stay indoors，and asked schools to keep children indoors.
   The emergency service Magen David Adom reported that it had treated more than 300 Israelis suffering from breathing problems，and that hospitals had more respiratory-related patients，including a large number of the elderly and those with asthma and related conditions.
   The domestic Israeli airlines Arkia and Israir continued to ground their flights to Eilat because of reduced visibility.
   The sandstorm has affected Egypt，Jordan，Iraq，Lebanon and Syria，where at least five deaths have been reported.
   "There has been nothing that came close to the magnitude（規(guī)模）of this sandstorm，" said Daniel Rosenfeld，a professor with the Institute of Earth Sciences at the Hebrew University in Jerusalem.
   "While Israel has experienced a number of sandstorms in the past，they started from the Sinai Desert and the Sahara Desert to the south and were joined by winter windstorms that cleared the air，" he said.In this case，the storm comes from Syria and Iraq to the north and east.
   Because the storm is hitting during the summer，at a time of both little wind and severe heat and humidity（潮濕），forecasters expect the particles （顆粒） to remain in the air throughout the weekend and possibly into next week.
   "This is really puzzling，said Rosenfeld，adding that he and his colleagues will conduct research into the origins of the unprecedented （前所未有的） storm.

（1）What's the probable meaning of the underlined word "ground" in Paragraph 4？

C

C

A．a(chǎn)dd.
B．reduce.
C．stop.
D．fuel.
（2）It can be learned from the text that the sandstorm

B

B

.
A．happened in winter
B．showed no sign of weakening
C．came from Syria and Iraq to the south
D．could clear the air
（3）How did Rosenfeld feel about the origins of the storm？

A

A

A．Confused.
B．Upset.
C．Confident.
D．Happy.
（4）Where does the text probably come from？

B

B

A．A novel.
B．A news story.
C．A geography book.
D．A travel guide.