认真阅读下列短文，并根据所读内容回答问题。
American pilot Frank Webb first flew a glider at the age of 14, made his first flight alone on his．16th birthday and got his commercial pilot's licensee （执照）on his 18th birthday．
After serving in the US Navy for 20 years, being a Boeing flight instructor, and working with Alaska Airlines for more than three years, Webb signed a contract with Shenzhen Airlines last May to captain domestic routes in China．As an experienced pilot, he still feels the same nervousness as he felt on his first fight.
Captain Webb said that the "Sept．11" incident did not have a direct influence on his decision to move to China to work．"Safety is in fact tighter in the United States and I am not worried about a terrorist attack," he said．"The main reason I came to China was that my children will have a chance to see the world and experience international living．"
Webb has not experienced any in-flight emergencies（紧急情况） during his term in China although he said the weather here was generally more changeable than in the United States．"The weather changes tend to be great from north to south．We may be flying in a snow storm in Harbin, and then later that same day we may be flying through a tropical rain shower approaching Shenzhen," Webb said．
While Webb had more flexibility（灵活性） to deal with the weather in the United States, he said air traffic control in China was more strict and allowed fewer deviations（偏离）．
Speaking of planes often being late in China, Webb said that in America, being late was one of the few things that would get him in trouble．"In China, on the other hand, it seems there are many things that can get you in trouble with the boss, but being late is not one of them．" Webb does everything in his power to keep his flights on schedule．
"They provide really excellent service during flights．Western flight attendants just serve passengers．But the Chinese attendants will also check on the crew to see if we need anything," Webb said．
Why did Webb sign a contract with Shenzhen Airlines? （no more than 20 words）
What is "glider " （in Paragraph 1）? （no more than 5 words）
What in the flight Webb met in China increased his difficulty? （no more than 5 words）
Is Webb's flight often late? Why? （no more than 20 words）
What can you learn from Webb's words in the last paragraph? （no more than 10 words）