If you go to fast food restaurant, you can see a lot of teenagers. Today,1teenagers are  2 because of their favorite food. Most teenagers 3junk food 4 a lot of fat, salt and sugar.

    5 bad eating habits are more than junk food. We find many teenagers eat6 Some don't have 7 before they go to school. During the day, some don't 8a proper meal for lunch. In a survey 9 one school, scientists found that over 65% of the students didn't have 10 healthy diet.

    Parents today also 11 about their children's diet. Some doctors give the following 12

    Teenagers shouldn't eat 13 junk food .Teenagers shouldn't eat food with much14 Salt can cause high blood pressure in the future.

Teenagers should eat food without much fat, oil and sugar.

    Teenagers15 to eat some fruits and vegetables every day. Fruits and vegetables are rich in vitamins and they have little fat.

1919年6月5日，一个日资纱厂的工人突破租界巡捕的武装包围，举行罢工，声援学生运动；商务印书馆、中华书局的工人也参加进来，罢工达到高潮时，参加人数达六、七万。这场工人罢工斗争应发生在(    )

1950年10月中国人民志愿军高唱“雄赳赳，气昂昂，跨过鸭绿江！……”的战歌，开始了（    ）

设f(x)为可导函数，且满足条件$\underset{x\to 0}{\lim }\frac{f(x+1)-f\left(1\right)}{2x}=3$ ，则曲线y=f(x) 在点 (1,f(1)) 处的切线的斜率为（   ）

用括号内所给动词的适当形式填空。
The garden is the best place ____ (grow) flowers.
This pair of jeans ____  (match) his white shirt.
Listen! How wonderful the music____ (sound) ！
 Mary, ____  (not be) afraid of the dog. It never bites.
 Keep quiet, the students ____ (prepare) for the coming exam.
____  (ride) a bike to school is good for your health.
Sandy spends a lot of time____  (chat) with her e-friend on the Internet.
How long does it take you____ (walk) to school every day?
I don’t have any ideas, I don’t know where ____ (go).
Would you like____ (drink) a cup of tea?