北回归线（Tropic of Cancer）
参考答案：
太阳光线在地球上的直射点在一年内可能达到的最北点所在的纬线。
1标准大气压能支持______高的水银柱．
-I hear that you will be on travel again.
-Yeah.My boss __________ for me to discuss business details with someone from another company.[ ]
A．asked
B．arranged
C．sent
D．called
