寨卡病毒是一种能通过蚊虫和母婴传播的病毒。寨卡病毒引起的传染病在人群中传播必须具备三个环节,被寨卡病毒感染的病人属于(　　)

下列函数中，一次函数是（　　）

T₂噬菌体在大肠杆菌细胞中增殖时，不需要下列哪种酶参与

短跑运动员5秒跑了50米，羚羊奔跑速度是20米/秒，汽车的行驶速度是54千米/时，三者速度从小到大的排列顺序是（　　）

阅读下列材料，从A、B、C三个选项中，选出最佳选项回答问题或完成句子.
    Miss Miller, The English Teacher wants to know about her students. She asks them some questions. The next are some of the students' answers(回答):

First name: Grace       Last name: Smith           Class: 1 School things: 2dictionaries, 4 pencil boxes, 8 notebooks

First name: Tony        Last name: Green          Class: 2 Things and positions: Watch: on the table        Volleyballs: under the desk Keys: in the schoolbag      Computer games: on the sofa

First name: Alice          Last name: Smith         Class: 3 Likes: apples, carrots, chicken, strawberries Doesn't like: bananas, salad, ice-cream