题目

用方框中所给单词的适当形式填空，每个单词限用一次。 danger, health, lucky, carrot, cross 16．---How about the kids in your neighborhood ?  --- They are happy and ____________. 17．You must be careful when you __________ the street. 18．---I passed the last exam.   --- Oh, you’re really a _________ dog. 19．---Can I help you, madam?   ---Two kilos of ___________, please. 20．Now lots of wild animals are in _________. We must try our best to protect them. 如图，若茎的a侧生长素浓度在B点以下的浓度范围内，下列对b侧生长素浓度范围的描述较为准确的一项是 [　　] A． 在BD范围内 B． 在OA范围内 C． 在BC范围内 D． 在BA范围内