Một tia sáng đơn sắc đi từ môi trường thuỷ tinh chiết suất \(n = \sqrt 2 \) đến mặt phân cách với không khí, điều kiện góc tới \(i\) để có phản xạ toàn phần là:
A.\(i \ge {30^0}\).
B.\(i \ge {40^0}\).
C.\(i \ge {35^0}\).
D.\(i \ge {45^0}\).

\(2.\left| {x - 1} \right| = 3x - 5\)
A.\(S = \left\{ {3;\dfrac{7}{5}} \right\}\)
B.\(S = \left\{ 3 \right\}\)
C.\(S = \left\{ {\dfrac{7}{5}} \right\}\)
D.\(S = \left\{ {3;\dfrac{5}{3}} \right\}\)

According to the passage, why were hamams important places for Islamic people?
A.They had to wash themselves before their daily prayers.
B.They would pray at hamams before bathing.
C.They met with other followers at hamams for social chatting.
D.They could relax there before their prayers every day.

Hòa tan hoàn toàn 3,42 gam hỗn hợp gồm Fe2O3, MgO, Al2O3 trong 400 ml axit H2SO4 0,2M (vừa đủ). Sau phản ứng, hỗn hợp muối sunfat khan thu được cô cạn dung dịch có khối lượng là
A.5,81 gam.
B.6,81 gam.
C.9,82 gam.
D.4,81 gam.

They ______ table tennis when their father comes back home at 5 p.m. tomorrow.
A.will play
B.will be playing
C.play
D.would play

An enormous amount of money has been wasted on this advertising campaign. 
A.a great deal
B.a limited number
C.a few
D.a small amount

Các Hội Cứu quốc của Mặt trận Việt Minh được bắt đầu xây dựng từ
A.trung du, miền núi.
B.đồng bằng, trung du.
C.miền núi.
D.miền xuôi.

Khi xóa đi chữ số hàng trăm của một số tự nhiên có ba chữ số thì số đó giảm đi 9 lần. Tìm số có ba chữ số đó.
A.150 hoặc 225.
B.350 hoặc 295.
C.450 hoặc 275.
D.450 hoặc 225.

He raised his hand high. He wanted to attract his teacher’s attention.
A.Because his teacher attracted him, he raised his hand high.
B.To attract his teacher’s attention, he raised his hand high.
C.Though he raised his hand high, he could not attract his teacher’s attention.
D.He had such a high raising of hand that he failed to attract his teacher’s attention.

She is an honest person. She is also a very friendly one.
A.She is an honest but friendly person.
B.She is not only an honest but also a very friendly person.
C.Though she is an honest person, she is friendly.
D.Being honest is necessary to become friendly.