After the mass shootings at Sandy Hook Elementary School, President Obama ordered his members to ________ solutions to gun violence.

Try not to cough more than you can ______ since it may cause problems to your lungs.

China has         in producing clones of cows and goats, and continues to research ways          _______ can benefit mankind.

Learn some relaxation exercises and do them every time you feel________.

 Thanks to the Party’s opening and reform policy, people in China are _____ than they were thirty years ago .