2-2.Christopher Gardner has never seen his fatheruntil the year when he is 28 years old.

In one day, Brandon can either plow 10 acres or plant 20 acres. In one day, Christopher can either plow 14 acres or plant 14 acres. Brandon and Christopher can A: gain from exchange if Brandon specializes in planting and Christopher specializes in plowing. B: gain from exchange if Brandon specializes in plowing and Christopher specializes in planting. C: exchange, but only Brandon will gain from the exchange. D: exchange, but only Christopher will gain from the exchange.

America was named after Christopher Columbus.

Christopher Columbus discovered America in 1492.

3. Shortly after Christopher was operated on, __________.

Faustus is a character created by Christopher Marlowe.

Christopher Columbus was the first person to cross the ( ) Ocean.

christopher agrees that B is an awesome score for a restaurant

Washington D.C. is named after . A: the U.S. President George Washington B: Christopher Columbus C: both George Washington and Christopher Columbus D: none of them

【单选题】NO 2 、NO 2 - 、NO 2 + 键角大小关系正确的是 。 A. NO 2 > NO 2 - >NO 2 + B. NO 2 + >NO 2 >NO 2 - C. NO 2 - > NO 2 >NO 2 + D. NO 2 + > NO 2 - >NO 2