You should feel content, as the design can’t be done any ______.

In the new curriculum, some courses are        , while others are optional for middle school students.

Philosophical problems arise when people ask questions that, though very        , have certain characteristics in common.

------ This is such an interesting book ______ everyone likes to read .------Yes , but there are few such books _______ in the bookstore now .

In their country the king has _____ power while the government are in charge of most affairs.