__________，many people go in for them and benefit from them.
| A．However some sports are challenging |
| B．However challenging some sports are |
| C．No matter how challenging are some sports |
| D．No matter how some sports are challenging |
The doctor said there was ______ with her, but she could not help worrying.
| A．serious something | B．nothing serious | C．something serious | D．serious nothing |
. ___________ she was chosen made us very happy.
| A．What | B．That | C．Why | D．How |
Ten years ________a long time in one's life.
| A．has been | B．are | C．is | D．have been |
— It’s the office! So you know eating is not allowed here.
— Oh, sorry.
| A．must | B．will | C．may | D．need |
It is known to all that ____ computer was invented in the USA.
A. that B. / C. the D. one