题型:单项选择题 It was announced that only when the fire was under control ________to return to their homes.[ ]A. the residents would be permittedB. had the residents been permittedC. would the residents be permittedD. the residents had been permitted 查看答案
题型:单项选择题 下列说法正确的是()A.人体细胞进行细胞呼吸产生CO2的场所不一定是线粒体B.人体中能产生激素的细胞一定能产生酶,可能会释放神经递质C.DNA的主要合成场所是细胞核;RNA的主要合成场所是细胞质D.对白化病基因携带者而言,除成熟红细胞外,其体内所有细胞均含有白化病的致病基因 查看答案