桰 haven’t been to Guilin yet.

桰 haven’t been there, __________.

A．also B．too C．neither D．either

I ________ to Beijing yet.

1. A.
   haven't gone
2. B.
   have gone
3. C.
   haven't been
4. D.
   have been

I have been to Guilin, but I haven't been _________ else ________.

1. A.
   anywhere; already
2. B.
   somewhere; yet
3. C.
   everywhere; yet
4. D.
   anywhere; yet

Scientists think that there has been life for__31_ of years. However we haven’t found life on other planets _32_ . The earth is a planet and it _33__ around the sun. Seven other planets also go _34_ the sun. The sun and its planets are __35  the solar system. The solar system is a small part of our galaxy.
Scientists __36_ lots of spacecraft to look at other planets in the solar system, and some spacecraft have gone __37_ the solar system. However, no one __38_ any life in space yet.
But why has no one from other planets sent us a message ? Have they tried to send _39_ to us ? _40_so many stars in the universe, are we alone, or is there life out there in space ? We don’t know.