（）makes men different from the other animals is that they can think and speak.

单项选择题（）succeed in everything we do.

A. Only by working hard can we
B. By only working hard we can
C. Only we can by working hard
D. Only by working hard we can

单项选择题He was made （）his working because of his poor health.

A. to give up
B. given up
C. give up
D. giving up