He has been reading it for two hours.
present perfect continuous-он начал читать книгу 2 часа назад,и все это время читал её.он её до сих пор читает или только-что закончил.
he has read 53 pages so far.
present perfect.
он прочитал пока 53 страницы .возможно ещё прочитает.
Mary is not walking along the streen
Is Mary walking along the street?
Sister doesn't cook well
Does sister cook well?
The children are not singing in the room
Are the children singing in the room?
Pam sometimes goes to the cinema on Saturday
Кино очень популярно, но меньше, чем это было в начале 20-го века.
You can not allow your child to spend at the computer too long - even off the computer and involves every time with the vagaries and sometimes with scandal (very much interesting thing - the computer; many children vostrinimayut problem like this: My screen goes blank - holiday ends).When we talk about dosing on the computer, we mean not only a negative impact on the child's body all kinds of radiation from the monitor, but the burden on the eyes (especially if the monitor is defective or poorly configured); it is important to know the following: a child who is too much "sits at the computer," in one way or shyuy least loses touch with reality.<span>The time during which the child is able to communicate with the computer, small: a child of primary school age - is 20-30 minutes; for a child of secondary school age - 30-45 minutes; child school age - about an hour. Of course, the time that you can spend at the computer, depends largely on the type of cathode ray "tube", which is a key element of the monitor; safer for health are tube Trinitron, SonicTron, DiamondTron; monitors the future called LCDs. If the home computer is equipped with one of the safest monitors, while working in front of the child so the monitor can be somewhat increased.</span>