我国确立（）为一项基本国策。A.民族团结 B.扶贫 C.环境保护

根据短文，把下列句子补充完整。（5分）

One day , Mrs.Wilson took Tracy and Aben shopping . They went to the supermarket in the new shopping center .

“ Why do you buy things here ?” Tracy wanted to know .

“ Because it is cheaper here than the store on the corner ,” Mrs.Wilson said . “ Help me check the price .”

The Wilsons were not rich , so Mrs.Wilson was always careful with her money . She looked carefully at the prices of things .

She bought a lot of things in the supermarket . When they got home , the children said , “We don’t think you saved any money by going to the supermarket .”

“ Of course , I did ,” Mrs.Wilson said , “ Everything was cheaper there .”

“ We know ,”the children said , “But we came home by taxi because we had too much to carry .The taxi fare was more than the money that you saved !”

Mrs.Wilson added everything up . Her children were right .

“ Well done ,” she said . “ Next time we’ll do our shopping near our home .”

小题1:Mrs.Wilson went to the supermarket to _______ things because they are ________ there .

小题2: Mrs.Wilson was always _________ with her money because the Wilsons were ________ .

小题3: Mrs.Wilson’s ______ helped her check the ________ when they were in the supermarket .

小题4: After they did some shopping , Mrs.Wilson and her children went home ______ _______.

小题5: The Wilsons couldn’t walk home because it was too _______ away from the supermarket to their home , and they had too __________ things .

垒球比赛中内场防守队员有（）名。

对以自然选择学说为核心的现代生物进化理论的正确理解是 

①环境改变使生物产生适应性的变异 ②隔离是新物种形成的必要条件 ③变异是不定向的 ④变异是定向的 ⑤自然选择使种群的基因频率定向改变并决定生物进化的方向 [ ]

A．②④⑤

B．②③⑤

C．①②④

D．①③⑤

某报关员遗失了报关员证，应及时向注册地海关书面说明情况，并登报声明作废。海关应当自收到情况说明和报刊声明之日起()内予以补发。

A.7日

B.15日

C.20日

D.30日

蒸汽管网进水的判断依据是（）。

A、管网压力不稳定

B、蒸汽压力突然降低

C、蒸汽温度突然降低

D、打开管线低点进行排放，其中有水排出