阅读下面短文，从短文后各题所给的四个选项（A，B，C，D）中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
For centuries, magicians have used various ways to shock the audience. We all have seen how a   36   performer carefully steps   37   a bed of burning coals -- barefoot. Then he walks across   38   a single burn on his feet. Is it mind over matter, or is it just physics? As it turns   __39  , walking on burning coals isn’t that hot as   40  . “The coals are hot enough to   41__  you, but if you walk quickly across them you   42   being burned.” says Jonathan Hall, a physician at Penn State University in Eric Pennsylvania.
That’s because some coals are made   43   burning wood chips. Wood has two   44__   properties（特性）for fire-walking, explains Hall. First, wood is an insulator（绝缘体）--it doesn’t   __45   heat very well. “It   46 _ time for heat to travel   47   the wood to your feet.” Hall says. If the performer walked across red-hot metal   48  , that would truly be   49  , because metal conducts, or transmits, heat very well. The metal would   50   burn a performer’s feet.
Second, wood has a low specific heat-- it doesn’t take much heat to   51   its temperature. Heat is a form of   52  . Temperature is a   53   of heat, in units of degrees. So   54   the coals are hot, the value（数值）of heat energy they contain is low. Thus, a well-trained performer can   55   such an amazing result.
Still, you don’t want to walk on burning coals, do you?

A．daring B．dare C．rough D．fearful

A．at B．over C．on D．above

A．with B．within C．without D．over

A．out B．on C．off D．in

A．imagine B．imagined C．imagining D．to imagine

A．fire B．burn C．light D．flame

A．prevent B．keep C．ignore D．avoid

A．off B．from C．of D．in

A．ideal B．classic C．favorite D．standard

A．transmit B．communicate C．bring D．send

A．gathers B．takes C．gains D．stands

A．through B．into C．over D．pass

A．unhappy B．unharmed C．unhealthy D．unprepared

A．charming B．magical C．tricky D．fashionable

A．instantly B．constantly C．frequently D．lately

A．produce B．raise C．construct D．create

A．power B．source C．energy D．strength

A．measure B．rank C．estimate D．rate

A．what if B．however C．as if D．even though

A．achieve B．arrive C．draw D．take