The mobile phone is useful to us, and we can use it _______others at any place.A. call B. calling C. to call
—You can't imagine ________ fantastic fun online chatting is. —Really?But it may cause a lot of trouble sometimes.
It is pretty well understood ________ controls the flow of carbon dioxide in and out the atmosphere today.
A plan has been put forward ________ more graduates should go to work in the country.
After three hours'climbing,they reached ________ they thought was the place they'd been dreaming of.
Engines are to machines ________ hearts are to animals.