A:whe
B:during which
C:since the
D:since whe
如图,点B在AC上,BD⊥BE,∠1+∠C=90°,问射线CF与BD平行吗?试用两种方法说明理由.
化学源于生活,生活中蕴含着许多化学知识.
If you want to see a doctor, you can go to the ______.
Lisa wants to _______ us her new pictures.