光效高、寿命长、能制成各种不同光色、应用日益广泛的光源为( )。
A．气体放电光源
B．热辐射光源
C．钨丝灯
D．卤钨灯
参考答案：A
Now an increasing number of middle school students go abroad for further study at their own ________, trying hard to realize their dreams.
A．price
B．cost
C．expenses
D．pay
隋性食物，食用后极易消化，在体内不易堆积尿酸及毒素，消化后在身上产生的能量使身体变得健康轻松和精力充沛
