Chengdu is a city _______ you hate to say goodbye once you have visited it.
| A．in which | B．at which | C．to which | D．with which |
33. If I_________you would drop in, I would have stayed home waiting for you.
| A．have known | B．knew | C．would know | D．had known |
32. ––When will you be back, Peter?
––________a couple of days.
| A．On | B．In | C．For | D．By |
31. All books ______ to the library more than three days late will be subject to a fine.
| A．return | B．returning | C．to return | D．Returned |
30. When he was only thirty years old, he had already experienced______most people only experience when they are much older.
| A．what | B．which | C．who | D．When |
29. ______ in the sports world, a sportsman needs to train constantly to keep himself in best condition.
| A．Survive | B．Surviving | C．To survive | D．Survived |