A：将两种金属相互刻画
B：将镁条放入硫酸亚铁溶液中，发现镁条表面变黑
C：将铁片和镁条分别在空气中灼烧
D：将铁片、镁条分别放入同样的稀盐酸中
– What's the matter with Tommy? – He is ____________.– Oh, you can tell him to share worries with his friends and ____________.
用一副三角板画角,不能画出的角的度数是（）
