【单选题】已知 Na 2 SO 3 晶体与浓硫酸可发生反应: Na 2 SO 3 + H 2 SO 4 ( 浓 ) == =Na 2 SO 4 + SO 2 ↑ + H 2 O 。如图所示: 在注射器中加入少量 Na 2 SO 3 晶体,并吸入少量浓硫酸 ( 以不接触纸条为准 ) 。则下列有关说法正确的是 ( )
【简答题】Soccer is a popular ______ for a variety of _________. Firstly, players need to use their _________ and ______ their ________ to play soccer. __________ a good level of fitness helps to ________ _____...