-"Please __________why you're so late," said his girlfriend.
He wrote to tell me that there was no need to worry about him and he had offered to clean the community __________ a week's accommodation.
He is teaching me French __________ my teaching him Chinese.
The committee __________ over the problem among themselves for two hours.
—Liu Fang, I don't know you can play the Pipa and Guzheng so well.—Well, actually I __________ it since I was six years old.
Betty and Louis __________ with each other at first sight and they __________ in love for five years ever since.