Cho đường tròn (O;R). Từ điểm P ở ngoài đường tròn kẻ các tiếp tuyến PA, PB ( A, B là hai tiếp điểm ) và đương kính AC của đường tròn.

a. Chứng minh tứ giác PAOB nội tiếp một đường tròn

b. Chứng minh PO//BC

c. Cho PO=2R (R=5cm), tính số đo góc AOB và diện tích hình quạt tròn AOB (ứng với cung nhỏ AB)

1. If he... Call me, I won't come

A. Isn't

B. Doesn't

C. Didn't

D. Don't

2. The old man walks.... to the park every day.

A. Slow

B. Slowly

C. Quick

D. Bad

3. I am... You didn't tell me the truth.

A. Disappoint

B. Disappointed

C. Disappointing

D. Please

4. The doctor suggested that you should... in bed some days.

A. Stay

B. Stayed

C. Staying

D. To stay

READING.

Electricity is the most common form of energy today. In the modern world electricity is very available at the touch of a switch. Electricity has many uses. The commob use of electricity is to provide artificial lighting. In factories, electricity is used to light up the work place. It is also used to operate air-conditioners, computers and many other machines. Electricity is also used to power many appliances that we have in our homes. Such appliances include televisions sets, computers, electric fans, irons and many others. Modern man will most probably be lost without electricity.

A. What is the most common form of energy today?

B. Is electricity very unvaible at the touch of a switch in the modern?

C. Do people use electricity to light up the work place and operate air-conditioners computers and many other machines?

D. What will happen to modern man without electricity?

WRITING

1. There was noise outside. The students kept on studying (thought)

2. Mr. Linh works for a company. This is company makes furniture (which)

3. The doctor is very kind. He has just examined my brother. (Who)

4. She comes here. They will take her to the zoo. (If)