下列关于功率的说法中，正确的是（ ）

2×9＝____ 9×5＝____3×6＝____ 2×6＝____

1×1＝____  5×7＝____  2×2＝____3×2＝____

5+6＝____  3×4＝____ 9×3＝____ 5×5＝____

7×4＝____  6+3＝____  6×5＝____ 7×2＝____

家鸽的生殖发育方式比青蛙的高等，主要体现在哪些方面？（ ）
①卵生 ②胎生 ③体内受精 ④体外受精  ⑤卵外有卵壳保护 ⑥有孵卵、育雏行为

    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.