Маємо сталь двох сортів, один з них містить 5%, а інший 10% нікелю. Скільки тон кожного з цих сортів потрібно взяти ,щоб одержати сплав, який містить 8% нікелю, якщо у другому шматку нікелю на 4 т більше , ніж в першому?

Во сколько раз легче протянуть брусок по столу, чем поднять его, если коэффициент трения между бруском и столом равен 0,5?

Определите массовую долю кислоты в растворе, если для приготовления взяли 80г. воды и 20г. кислоты.

1) I'm very busy at the moment. I ....for my English exam
A) am preparing B) prepare C) have been preparing D) am going prepare E) were going prepare

2) He is fond of....speeches in public

A) make B)makes C) making D)doing E)to make

3) She....the article and wants to show it to the teacher

a)was translating b)translated c)has translated d)translate e)to translate

4) There was...to eat and drink after the party

a)many b)lot of c) a lot d) lots of  E) much

5) ...that strange man sitting over there?

A)whose B)which C)who's D) who E) what

6) A kangaroo has such strong legs...it can jump over a car.

A) so B)so as C) as D)that E)this

7)The telephone was...by Alexander Graham Bell.

A) discovered B)invented C)explored D)studied E) to study

8) This program...me a lot of money.

A)cost B)costed C)had costed D) was cost E)were cost

9) It happened...our way home

A)in B) on C) for D) about E) by

10) By the time we arrived at the station, the train...

A)left B) has left C) had left D)was left E) to left

11) Everest is...mountain in the world

A)    high B)highest C) the higher  d)the highest E) more highest

12) If he lived in the country he...happier

A) was B)is C) will be d) would be E) were