All classes of this school are______with modern______ . 

 —How wise of you to come round, but why?— ________that all is right. 

       form the moon, our earth with water        .seventy percent of its surface, appears as a blue ball.

 ____ for its well-preserved ancient Tibetan houses, Dukezong was one of the most popular resorts in Shangri-la.

When ________ questions in class, one should answer them as clearly as possible.