The sunspot came into its active stage last year, that happens once every eleven years.
The government has taken some measures to solve the shortage of electricity, but it may be some time ____________ the situation improves.
Mary had to go to a meeting,so she left her children ___________ at home.
A cell phone could ___________the energy which could activate your brain.
I think it a great honor ___________ to visit your country.
— What do you think of modem music? — It is often considered not as good as ___________ of the past.