______ in London, the penniless American wandered on the pavement, ______ to find a job to make a living.

If ____ in, the viruses can result in illness or even deaths.

When a person is absent-minded, he is likely to miss key information ______ on to them.

_______ his scientific work, he has no time to care for his family affairs, which his wife always complains about.

 With all the books he was interested in ________， he left the library and went back to his dorm.