在文中横线处填入下列语句，衔接最恰当的一项是（    ）

当陈阵猛地转头向山谷望去时，他几乎吓得栽下马来。距他不到40米的雪坡上， 在晚霞的天光下，竟然出现了一大群金毛灿灿、杀气腾腾的蒙古狼。               。 整个狼群不下三四十头。

①狼群中一头被大狼们簇拥着的白狼王，它的脖子、前胸和腹部大片的灰白毛，发出白金般的光亮，射散出一股凶傲的虎狼之威。

②此时，十几条蹲坐在雪地上的大狼呼地一下全部站立起来，长尾统统平翘，像一把把即将出鞘的军刀，一副弓在弦上、居高临下、准备扑杀的架势。

③离他最近的正好是几头巨狼，大如花豹，足足比他在北京动物园里见的狼粗一倍、高半倍、长半个身子。

④全部正面或侧头瞪着他，一片锥子般的目光飕飕飞来，几乎把他射成了刺猬。

    Christmas is coming. Stephen can see it everywhere he 1 There are Christmas things to sell in the shops and Christmas trees in the park. But it is only in late 2 . Stephen thinks this is wonderful. He likes Christmas very much. To celebrate it for a month is not enough.

     He went into a clothes shop to buy 3 . He found a perfect (完美的) pair.

    "Just these, sir?" asked the shop assistant.

    "Yes, please," 4  Stephen.

    "They look a little big for you. Are you sure they will 5 ?" asked the shop assistant.

    "Oh, they will be fine," said Stephen,

    It was 6 the trousers were a little big. But they  7  to be. Every Christmas Stephen 8 as Father Christmas and works in the local shopping mall. Children like to take photos with him.

    Stephen walked out of the 9 and smiled happily. What 10 he do this Christmas?

处于n=5能级的大量氢原子，向低能级跃迁时，辐射光的频率有（   ）

下列有关酶与ATP的应用的叙述中，不正确的是： （   ）