Jim enjoys listening to pop music. _______________. .
______42, Dmitry Medvedev becomes the youngest president of modern Russia. —I know he ever became very ______ his students at university. [ ]
This is 3-D printer. And this is an artificial (人工的) ear. Can you believe that scientists printed this artificial ear by this 3-D printer?
There will be _____air pollution if there are_____ people driving. –I hope the air will be fresher soon.
There are ________ days in a year.