If we use new types of energy， they will produce little pollution. ______ they cost very little and never run out.

Land animals are believed ______ from seaanimals.

Many of the big world sports events are _______by wealthy big companies, who hope to advertise their companies or their products.[ ]

When did your father _______ your mother

_The girl is new here and she lives ____, so she seems _______._We’d better ask her to play games with us.