Directions: In this section, you are to write an essay of about 200 words within 40 minutes. Your essay should be based on the information given below. 现在许多人愿意乘飞机旅行。随着我国民航事业的迅速发展,全国各大城市兴建了许多现代化的机场。乘飞机旅行有许多长处(方便、快捷、省时、舒适等); 但是,空中旅行也有许多不足