核素治疗病室中,无活性区是指()
A.病房
B.患者活动区
C.放射性核素储存场所
D.医护人员工作场所
E.放射性药物分装场所
参考答案:D
—Would you like to go to the cinema with me tomorrow afternoon?
—I’d like to, Mum, but I ________ to a party by Jane. It is her birthday.
A.am invited
B.was invited
C.will be invited
D.have been invited
某同学在做植物细胞质壁分离的实验时,观察到紫色洋葱表皮细胞的中央液泡逐渐缩小,这说明()
A.洋葱表皮细胞是活细胞
B.细胞液的溶质透出细胞
C.蔗糖溶液浓度小于细胞液浓度
D.细胞壁收缩导致中央液泡失水