Jack tried to play a trick ______ his sister but she wasn’t taken ________ .

sent, 1 in every 10 people isaged 60 years or older, ______ in 2050, 1 in every 5 people will be aged 60years or older.

I failed again，but my parents encouraged me and told me that failure________the mother of success.

To tell the truth, I would rather I ________ the pain instead of you. You don’t know how worried I was.

Standing on the top of the hill, one would not do anything, but _____ the flowing of the clouds around me.