A:120°
B:80°
C:60°
D:50°
①洪水泛滥,大量树木被淹 ②烧荒垦地,种植大豆
③非法砍伐,走私贵重木材 ④气候恶化,树木病虫害严重
— It seems that Mr. Wu is standing there.— It ______ be him because he called me from Canada just now.