clean up，care for，give up，the look of joy，try out，go on
（1）Many students want

to try out

to try out

for the volunteer program at an animal hospital.
（2）You should

clean up

clean up

your house.It's too dirty.
（3）Mary wants to be a nurse.So she volunteers at a hospital to learn more about how

to care for

to care for

the sick people.
（4）Alice told her friend that she

went on

went on

an exciting journey with her mother yesterday.
（5）I'll never forget

the look of joy

the look of joy

in her eyes when a 4-year-old girl sees all kinds of candies in the store.
（6）Those kind people

gave up

gave up

three hours to look for the lost kids.