1.   For Gieves the tailors, the extent to which clients indulged in running up bills regardless had become extremely serious.

2.   His expression became more serious as he listened to her story.

3.   His expression became serious as he listened to her story.

4.   In the last two weeks, the situation has become more serious, with riots and strikes spreading across the country.

5.   It became a standing joke that we would eventually work together, and then one day it became serious.

6.   It was now clear, however, that the position was becoming deadly serious.

7.   She dared not allow them to become too serious.

8.   When the band became serious, I thought this is a far more contemporary and interesting way to make an artistic statement.

9.   The emcee told some good boffs that kept the ceremony from becoming too serious.

10.   The drought is becoming very serious, no rain having fallen for nine months, in fact nothing but ruin presents itself.