Nbsp; выберите соответствующую видовременную форму сказуемого.
1. the abacus … about 5,000 years ago.
a) has emerged; b) emerged; c) had emerged; d) emerges;
2. the first all-electronic computer … by 1940.
a) developed; b) was developing; c) was developed; d) had been developed;
3. in 1694 pascal’s invention … .
a) was improved; b) improved; c) was improving; d) had improved;
4. the transistor … the large vacuum tube in televisions, radios and computers.
a) replaced; b) replaces; c) was replaced; d) was replacing;
5. scientists … to fit even more components on a single chip very soon.
a) will have managed; b) manage; c) will manage; d) ;
1. b (ago - признак Past Simple)
2. d (действие завершилось до какого-то момента в
3. a (конкретный год в признак Past Simple)
4. a (нет конкретного временного указания, но действие скорее всего в "заменил")
5. c (soon - Future Simple)