3.I can't find my notebook. Somebody __________________ it!

(1 Point)

has moved

moved

is moving

4.He __________ piano lessons when he ____________ a teenager.

(1 Point)

takes / is

took /was

has taken/was

5.Anne: Did you like the film “Lord of the Rings?”
Mary: “Yes, I _________ it several times.”

(1 Point)

see

saw

have seen

6.Paul: “_________________ to London”
Nam: “No, not yet. What it’s like”

(1 Point)

Are you going

Did you go

Have you ever been

7.John __________________ home when he went to college.

(1 Point)

leaves

left

has left

8.Modern medicine ___________________ the lives of millions of people.

(1 Point)

save

are saving

has saved

9.They __________ a volunteer project to help children in mountainous areas a few years ago.

(1 Point)

started

have started

start

10.I (wash)                       the dishes yesterday, but I (have)                   no time yet to do it today.

(1 Point)

washed - had

have washed - have had

washed - have had

11.I (not/ see)                   Peter since I (arrive)                           last Tuesday.

(1 Point)

didn't see - arrived

haven't seen - arrived

haven't saw - arrived

Viết các STP sau dưới dạng ps rồi thực hiện phép tính:

a, A= 12,(4) - 9,(3) + 0,(18)

b, B= 0,3(21).0,878:0,53(21)

Lập tất cả các tỷ lệ thức có thể từ 4 số trong các số sau (mỗi số chỉ chọn 1 lần): a, 4,6; 11,5; 3,5; 1,6

b, 0,4; 3,6; -4,5; 32,4; -0,5

Cho xOy=50 độ, gọi xOt, yOv là 2 góc kề bù với xOy. Chứng minh rằng: 

a) Hai góc xOt, yOv là 2 góc đối đỉnh. Tính số đo 2 góc đó.

b) Đường thẳng chứa tia phân giác của góc vOy cũng chứa tia phân giác tOx

Cho hai số hữu tỉ \(\dfrac{a}{b}\) và \(\dfrac{c}{d}\)(a,b,c,d ϵ Z; b,d ≠ 0)

Chứng tỏ rằng nếu \(\dfrac{a}{b}\) < \(\dfrac{c}{d}\) thì \(\dfrac{a}{b}\) < \(\dfrac{a+c}{b+d}\) < \(\dfrac{c}{d}\).

Áp dụng: Tìm 3 số hữu tỉ lớn hơn \(\dfrac{-6}{7}\) và nhỏ hơn \(\dfrac{-1}{3}\).

Giả sử x = \(\dfrac{a}{m}\); y = \(\dfrac{b}{m}\)(a;b;m ϵ Z, m ≠ 0 và x < y). Hãy chứng tỏ rằng nếu chọn z = \(\dfrac{a+b}{2m}\) thì x < y < z.