问题
选择题
—What did the teacher say just now?
—Sorry, I didn’t hear it. I out of the window.[ ]
A. look
B. looked
C. am looking
D. was looking
答案
答案：D
搜题请搜索小程序“爱下问搜题”
—What did the teacher say just now?
—Sorry, I didn’t hear it. I out of the window.[ ]
A. look
B. looked
C. am looking
D. was looking
答案：D
的焦点为F，抛物线上的点A到y轴的距离等于|AF|-1.