Cho tam giác ABC nhọn(AB<AC) nột tiếp đường tròn O ,hai đường cao BE,CF cắt nhau tại H.Tia AO cắt đường tròn O tại D 

a) Chứng minh bốn điểm B,C,E,F cùng thuộc một đường tròn

b)Chứng minh AF.AB=AE.AC và góc AFE = góc ACB

c) Gọi M là trung điểm BC.Chứng minh ME là tiếp tuyến của đường tròn đường kính AH

Chuyển sang câu bị động:

The gardener has watered the flowers
.................................................................................
I finished my work at 2 pm
.................................................................................
Bill is using the computer at the moment.
.....................................................................
They paid designers a lot of money.
.................................................................................
When did they decorate your living room?.
.................................................................................
We have to test these products.
.................................................................................
How do people pronunce this word?
.................................................................................
We must do something before it’s too late.
...................................................................................
People don’t use this dictionary very often.
.................................................................................
Someone gave Mary this present an hour ago.
.................................................................................
Has some one repaired this telephone
...................................................................................
They told me that your teacher was sick.
.................................................................................
The students have finished their work.
.............................................................................
They watched TV late last night.
...................................................................................
The will visit their grandma tomorrow
.........................................................................................

Giúp iem vs ạ