Read the following passage, then choose the correct answer to questions.     

    It can be shown in facts and figures that cycling is the cheapest, most convenient, and most environmentally desirable form of transport (21)______ towns, but such cold calculations do not mean much on a frosty winter morning. The real appeal of cycling is that it is so (22)______.It has none of the difficulties and tensions of other ways of travelling, (23)_______ you are more cheerful after a ride, even through the rush hour. The first thing a non-cyclist says to you is:“But isn’t it (24)______ dangerous?”. It would be foolish to deny the danger of sharing the road with motor vehicles and it must be admitted that there are an alarming (25)______ of accidents involving cyclists. However, although police records (26)______ that the car driver is often to blame, the answer lies with the cyclist. It is possible to ride in such a way as to reduce risks to a minimum.   It can be shown in facts and figures that cycling is the cheapest, most convenient, and most environmentally desirable form of transport (21)______ towns, but such cold calculations do not mean much on a frosty winter morning.

        It can be shown in facts and figures that cycling is the cheapest, most convenient, and most environmentally desirable form of transport (21)______ towns