John's success has nothing to do with good luck. It is years of hard work has made him what he is today.
| A．why | B．when | C．which | D．that |
No one expected house prices to fall, but _____ that's exactly what happened.
| A．moreover | B．thus | C．anyway | D．however |
Many people can't learn any lessons from the mistakes they've made _____ they get hurt somehow.
| A．whether | B．unless | C．if | D．as |
Painting from still images leads to a loss of sensitivity, which is _____ to an artist.
| A．absolute | B．urgent | C．especial | D．vital |
——Can I get out in the daytime?
——No. The school rules state that no child _____ be allowed out during the day, unless accompanied by an adult.
| A．shall | B．need | C．will | D．can |
People have come to understand _____ prevents so many Americans from being as happy as one might expect.
| A．that it is why | B．what does it that | C．why it does that | D．what it is that |