—Is there any vaccine(疫苗) against H1N1 flu that can be used on humans?—No, but scientists are working to develop ________ .

I like _____ in the autumn when the weather is clear and bright.

When you are reading fast, your eyes will be one or two word groups ahead ___your mind is taking on. 

All of us have the desire to visit the three main temples in Athens, especially ______ that contains a gold and ivory statue of Athena.

It’s said that he’s looking for a new job, one ___ he can get more money to support his family.