从倾角为θ的斜面顶点A平抛一物体，初动能为10J，物体到达斜面底端B时的动能变为130J，不计空气阻力，求斜面的倾角θ。
600
根据中文、首字母和句意完成句子。
1. A dancer needs a lot of _____ (能量) to dance.
2. It is i_____ for us to learn English well.
3. —Do you often e_____?
—Yes. I like swimming very much.
4. The girl c_____ her diet because she wants to be healthier.
5. We like playing c_____ games and chatting with our friends on the I_____.
6. I ate two pieces of b_____, two eggs, a bowl of n_____ and some v_____ for breakfast this morning.
7. Let's buy some potatoes and _____(胡萝卜).
8. How often do you eat_____(水果) and vegetables?
9. You should eat h_____ food and e_____ more.
10. This fruit is yellow and it t_____ sour.
患者，男，30岁，为去除烟斑，要求洁治。刷牙出血不明显，临床检查：大量菌斑、牙石，牙龈红肿不明显，探诊后点状出血，全口牙附着丧失2～3mm。
该患者没有坚持彻底的牙周治疗，1年后，因牙龈自发性出血、疼痛、腐败性口臭3天就诊，对此最可能的诊断是（）
A.牙周脓肿
B.急性坏死性溃疡性龈炎
C.顽固性牙周炎
D.牙周炎复发
E.疱疹性龈口炎
