a,chứng minh AD//CF

b,chứng minh AD//BE

tìm x,y biết:

x/4=y/5 và x²-3y²=-59

tìm x,y biết:

x/3=y/6 và 2x²-y²=-8

VII. Fill in each numbered gap with one suitable word to complete the following passage.

A long time ago, robots belonged to science fiction. But today, robots (1)______ real, and they are helping us. In the future, we will  all have robots. They (2)_____ clean the floor, wash the dishes, cook meals, take care (3)______ children, make drinks and do many other housework. I even think one day we’ll have robots friends. In Japan today, robot engineers are making robots to (4)______ old people. It’s still early days. I’d say we are another 20 to 30 years away from robots being everywhere in our lives. What will happen to us (5)______ the world is full of robots? Maybe one day we won’t be able to tell robots and humans apart.

22. That is .  .  .  .  .  book I’ve ever read.

23. It’s getting light. Shall I turn .  .  .  .  . the lights to save electricity? 

25. What does 3Rs stand .  .  .  .  .  ?. It’s Reduce, Reuse,  Recycle.

26. A robot can do .  .  .  .  . different things from looking after a baby to building a house.

28. I can’t come right now. I .  .  .  .  . when I finish my homework.

29. If you read more, your vocabulary will get .  .  .  .  . every day.

30. It is wrong of you to do this. This .  .  .  .  . never happen again!