There are several factors _______ in the economy _______ make it difficult to predict the future.
| A．operate; where | B．operating; which | C．to operate; that | D．operated; what |
It was in 1969 ______ two Americans went to the moon by spaceship.
| A．when | B．that | C．at that time | D．just then |
My mother insisted that I _____to school on foot.
| A．went | B．goes | C．go | D．going |
Since Margot found it difficult to settle in a new place, she felt ______ that the family had to move.
| A．upset | B．crazy | C．happy | D．easy |
The engine of the ship was out of order and the bad weather ______ the helplessness of the crew at sea.
| A．added to | B．resulted from | C．turned out | D．made up |
His calculation of the result of the exam _______ to the fact, but he failed again．
| A．approximated | B．focused | C．consisted | D．contracted |