Our visit to Alaska was a pleasant ________.

[　　]

________ it is to swim in the ocean!

[　　]

The tower of London is a great ________ to tourists.

[　　]

The ________ in that novel is one of adventure in exploring Arctic．

[　　]

Where the Nile enters the sea it ________ a number of smaller rivers.

[　　]

A newspaper ________ is an amusing drawing, usually about some event in the news.

[　　]

Rockets with ________ one stage are called step rockets.

[　　]

This is the right high way ________ the dock.

[　　]

Having a trip abroad is certainly good for the old couple, but it remains ________ whether they will enjoy it．

[　　]

We thought of selling this old furniture，but we've decided to_______ it．It might be valuable．

[　　]