A:60°
B:75°
C:90°
D:105°
某地以东是东半球,以西是西半球,以北是北温带,以南是热带,该地是( )
我国海洋总污染量的80%来自____ ,主要是____ 和生活污水.
This is my room (房间).I have a new desk and a chair.The book is on the desk.The ruler is under the book.My eraser is in the pencil box.My bag is on the chair.Where's my cat? It's under the chair.It's sleeping (睡觉).
下列变化中,没有新物质生成的是( )