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

English is used an official language in more than 70 countries.

________ Sunday morning, he cleaned his room. _______ the afternoon, he did his homework. __________ night, he watched Olympic Games.

If you don’t go to the meeting tomorrow, ________

下列各句中，语言表达得体的一项是（ ）