【单选题】---How many elephants are there in the zoo? --- There aren’t _______.
【单选题】In many countries, there aren’t sufficient water resources ________ for future development.
【单选题】There are many pears ______ the tree, but there aren't any birds ______ it. [ ]
【单选题】There ____________ many children in the classroom. [ ]
【多选题】如何挖掘农田土壤剖面及采集土壤农化样品?
A.
点数及布点:符合精度、均匀性、典型性、 代表性
B.
挖掘:不可在沟边、路边、房边、树边等;长1.5-2m、宽1m、深1.5m或地下水或母质,观察面朝阳,层土和下层土分放。
C.
农化土壤采集:一般采集农田混合土壤样品,采集3-5个0-20cm、20-40cm土样,按照四分法进行混合取样,写好标签,注明采样地点、时间、层次、采样人等。
【单选题】—There are many old houses in Beijing, aren’t there? —______ . It’s a city with long history. [ ]
【单选题】1921年7月23日,中国共产党第一次全国代表大会在上海召开。大会选举产生了党的领导机构( ),( )为书记。
【单选题】There orange juice in the bottle. [ ]
【单选题】There are ___________ boys. There aren't ___________ books. [ ]