—How many practical plans has your colleague made this month?—      . All have turned out disappointing.

_________ may have a chance to be successful if he tries his best.

Good health is __________ most people take for granted--- until they lose it .

–Let’s go to the cinema by taxi.-Don’t worry, we have __________ time.

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