用括号内所给动词的适当形式填空，必要时可加助动词或情态动词。

1. Ming went to Shanghai last year and _________(fall) in love with it.

2. All the people in the world hope there _________(not be) any pollution in the future.

3. Tom _________(watch) TV when his father got home yesterday.

4. If you _________(not start) early, you will be late.

 5. Marcia said everyone shouldn't _________(shout)in the dining room.

6. Scott is supposed _________(arrive) at the airport at eight o'clock.

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.疱疹性龊口炎