已知，若是的充分条件，则实数的取值范围是__________．
驱蚊草(又名蚊净香草)含有香茅醛，能散发出一种特殊的柠檬型香气，从而达到驱蚊且对人体无害的效果。驱蚊草是把天竺葵的原生质体和香茅草的原生
下列与DNA分子的半保留复制有关的叙述，正确的是（） A． DNA分子复制时，以一条链为模板，合成两条新链，两条新链构成一个新的DNA分子，
He came over to us as if his business cards among us． A．to pick out B．to give out C．wiping out D．setting
农作物生长需要含较多氮、磷、钾元素的化肥，下列化肥属于含磷复合肥料的是（ ） A.NH4NO3 B.Ca(H2PO4)2 C.(NH4)2HPO4 D.KNO3
James is a good student and he has lots of friends，but he also has a problem．Some older boys are bullying(欺负)him at school．James is very unhappy and he doesn't know what to do about it．Her
读“热力环流示意图”（a、b表示等压面），回答下列各题: 图中①、②、③、④四点的气压大小比较，正确的是 A．①＞② B．①＞③ C．①＞④
