--Would you please explain to me about the difference between the two phenomenon?
--I’m sorry, but that’s just _____ I’m puzzled about.
| A．why | B．what | C．which | D．where |
If you are ________ about Australia cities, just read the book written by Dr. Johnson.
| A．curious | B．anxious | C．mysterious | D．puzzled |
Mr. White will come to the party on Sunday, _______ he promised to every one of us.
| A．when | B．that | C．what | D．which |
Mary has recently got engaged ________ a foreign teacher, who has been engaged ________ education research for years.
| A．with; in | B．to; in | C．in; to | D．in; for |
Time ________ quickly. Three years passed before we knew it.
| A．went by | B．went on | C．went away | D．went off |
Mr. Smith is busy these days ________ a new book on how to develop a child’s reading skill.
| A．working out | B．working on | C．working for | D．working with |