For the safety, everyone _________ obey the traffic rules when he is driving or walking.
A. need B. must C. may D. could
This summer vocation I am going to do a lot of _________ to prepare for the senior high school.
A. job B. work C. invention D. service
--Did you see Mary and her sister this morning?
-- Yes, I saw _________ girls playing in the playground.
A. either B. neither C. any D. both
Although advertisements enable _________ to make decisions quickly, they sometimes cause lots of trouble.
A. we B. our C. us D. ours
Over 20 countries joined to search _________ Flight MH370 in the southern Indian Ocean.
A. of B. for C. in D. from
Nowadays many parents make their children study various subjects _________ weekends.
A. with B. at C. by D. to
