第二节：语法填空I have a friend who must be the sweetest, shyest per

第二节：语法填空
I have a friend who must be the sweetest, shyest person in the world. He is forty years old, rather short and 11 (skin), and has a thin moustache and even thinner hair on his head. Since his vision is not perfect, he wears glasses: 12 are small, round and frameless.
He always walks sideways so 13 not to inconvenience anyone. Instead of saying “Excuse me”, he prefers to glide by one side. 14 the gap is so narrow that it will not allow him to pass, Luke waits patiently 15 the obstruction (障碍物) moves by itself. Stray dogs and cats panic him, and in order to avoid them, he constantly crosses from one side of the road to the 16 .
He speaks in 17 very thin, subtle voice, so inaudible that it is hard to tell if he is speaking at 18 . He has never interrupted anybody. On the other hand, he can never manage more than two words without 19 (interrupt). This does not seem to irritate him; in fact, he actually appears happy 20 (be) able to utter(发出) those two words.