She devoted herself __________ to her research and it earned her a good reputation in her field. 

The schoolmaster hesitated ___ an instnat before he made the decision.

Two middle-aged passengers fell into the sea. ______, neither of them could swim.

A firm from New Zealand has revealed a set of robotic legs which they claim will soon allow ________ wheelchair-bound people to walk again.

Kathy has wasted so much time playing,  ___failing in the exam.