— Miss Yang doesn’t look well. What’s wrong with her?— Oh, she has some trouble ______ her baby well.
A:take care of
B:looking after
C:taking after
D:to look after
0.02×38.7×50=____
在一个大型平底烧瓶湿润的泥沙中插上几枝新鲜的枝条和一支盛有适量NaOH溶液的试管,烧瓶口紧包一个气球,使烧瓶悬浮在玻璃缸中某一位置(如下图)。自然环境下持续观察,最终可以发现烧瓶的浮沉情况怎样?请解释其中的原因。
溴乙烷在不同溶剂中与NaOH发生不同类型的反应,生成不同的反应产物.
— Four students in Qingdao stood in line against a man to save a woman teacher at the school gate.
— _________ great courage they had!