题目

当抗原刺激机体产生细胞免疫反应时，效应T细胞发挥的作用是 A．产生抗体使靶细胞裂解                  B．激活靶细胞内的溶酶体酶使靶细胞裂解 C．产生组织胺增强B细胞的功能         D．促进B细胞产生淋巴因子 答案：BDear Jenny, Please take these things to your brother: his math book, baseball, notebook, CDs, and video tape. The math book is on the dresser. The baseball is under the bed. The notebook is on the bed. The CDs are in the drawer. The video tape is on the table. Thanks! Mom1.Where is the math book?A.It’s on the dresser.B.It’s under the bed.C.It’s on the bed.D.It’s in the drawer.2.What’s under the bed?A.The math book.B.The baseball.C.The notebook.D.The CDs.3.The math book is       .A.Jenny’sB.Mom’sC.Jenny’s brother’sD.Tom’s4.The       are in the drawer.A.rulersB.booksC.CDsD.pens5.The video tape is        .A.on the tableB.under the tableC.under the bedD.on the bed