—Who helped Jessie with her English?—_______, she taught herself.

The mayor has offered a reward of $ 5000 to ______ who can capture the tiger alive or dead.

(2013·江西高考)________ can be good at something for 40 years if he doesn't love it.

The companies are working together to create _____ they hope will be the best means of transport in the 21st century.

Don’t be afraid of challenge; there is _____like it to bring out the best in a person.