The two countries once_______ into one, it will become a strong and powerful one in the world.
| A．joined | B．connected | C．unifies | D．united |
By the middle of the 21st century , the vast majority of the world’s population ________ in cities rather than in the country.
| A．are living | B．will be living |
| C．have lived | D．will have lived |
It is because people are likely to stay indoors ______ the virus can spread easily ______ people often catch colds.
| A．and, that | B．so, that | C．therefore, so | D．that, that |
He gave us a nod and muttered a “yes” after _______ seemed like hours.
| A．that | B．which | C．it | D．what |
In any case, parents should make clear _______, if any thing, the children are expected to pay for with the money.
| A．that | B．which | C．what | D．how |
Many new games are designed on the computers all the time; people of all ages ______ these games.
| A．are playing | B．had played |
| C．have been playing | D．play |