知圆C：（x﹣1）2+y2=2，过点A（﹣1，0）的直线l将圆C分成弧长之比为1：3的两段圆弧，则直线l的方程为（ ）
x﹣y+=0或x+y+=0
图6是“我国郑渝（郑州至重庆）高速铁路规划图（初步规划有①、②线两种方案）”，读图回答下题。
夏秋季节，①线经过的甲地附近有夜间多雨的现象。关于其原因的叙述，不正确的是
A．夏秋季节，空气中水汽含量大
B．谷底暖湿空气下沉，易形成降雨
C．处于河谷，水汽含量丰富
D．河谷地形，夜间山坡因辐射冷却，冷空气沿坡地向下流入谷底
The teacher asked us _____.
A．when did I finished my work.
B．why didn’t we tell him about it earlier.
C．what we were interested in
D．where we are going to have our lunch
x﹣y+
=0或
x+y+
=0
x﹣y+=0或x+y+=0