---What do you think of the twin sisters?---They are quite different. One is outgoing, __________ is very serious.
This summer vocation I am going to do a lot of _________ to prepare for the senior high school.
--Did you see Mary and her sister this morning?-- Yes, I saw _________ girls playing in the playground.
Although advertisements enable _________ to make decisions quickly, they sometimes cause lots of trouble.
Over 20 countries joined to search _________ Flight MH370 in the southern Indian Ocean.
Nowadays many parents make their children study various subjects _________ weekends.