16．Stargazing（觀星）is becoming popular in China.Young people often enjoy the night sky while camping or（1）
（ have）a picnic.
Usually，the best conditions for stargazing are dry air，clear nights and no light pollution.If you want to see the stars（2）
（clear），you can go to a mountain or the desert.The Ningxia Hui autonomous region is one of the great（3）
（ place）.More than 30，000 people go there every year.
（4）
telescopes（望遠鏡），these stargazing lovers try to watch the beautiful stars.If you don't have a telescope，you can also use a smartphone with a stargazing app.
China has（5）
long history of stargazing.To tell the time and work out the calendar，Chinese people have long looked at and studied stars.They（6）
（ make） the calendar by studying the moons and the stars.（7）
also studied the stars to predict unknown things.China has the（8）
（ old） complete star map — the Dunhuang star map.It was made by people in the Tang Dynasty and mapped more than 1300 stars!
Here are some tips for stargazing.First，check the weather.You can not star gaze（9）
the weather is fine.Second，it（10）
（ be） much safer if you bring a friend or parent along with you.Third，bring a sky map or use an app to find out what you see.Star Walk2 and Stellarium Mobile Plus are good choices.
