单项选择题

Questions 19 to 22 are based on the conversation you have just heard.

A．Discovering new life in space.
B．Studying meteorites.
C．Plotting the courses of asteroids.
D．Developing radar telescopes.

<上一题目录下一题>

热门试题

填空题

The food-borne disease may cause fever, vomiting, diarrhea and even ______.

填空题

obedience

Questions 19 to 22 are based on the conversation you have just heard. 您的浏览器不支持 audio 元素。