【原创】They are twins but they have different _____ .
Can you explain __________ the sun goes down in the west?
What an unforgettable experience ! I'll write it down __________ it is still fresh in my memory.
__________,many people go in for them and benefit from them.
Although __________ to be the best in a recent science competition, the students remain hard-working.
-You aren't looking well. Anything the matter?-I've been surfing the net too long. I'm a bit tired. I can hold on,__________.