Scientists in the UK have announced that the piranhafish’s reputation (21) a fearsome (22) may well not be deserved. The fish, which is found in the Amazon in Brazil, have been (23) as deadly carnivores (食肉动物) that work in shoals to overwhelm their prey and strip it of its flesh in seconds.
However, experts (24) St Andrews University say that piranhas are omnivores (杂食动物) that mainly eat fish, plants and insects. They form big groups not to hunt but to defend (25) against other predators, according to the team.
"Previously it was thought piranhas shoaled as it (26) them to form a cooperative hunting group," said Professor Anne Magurran. " (27) , we have found that it is primarily a defensive behavior."
Piranhas can be attacked by animals (28) dolphins, caimans and large fish, so forming a shoal is a good way of (29) being killed. Piranhas of (30) A. kill
B. killer
C. murderer
D. murder
| A recent report on population trend
conducted by the think (1) of the World watch Institute
identifies signs of slowing growth in some countries. It says populations in 32
countries—all in the industrialized world—have stabilized because of declining
birthrates. But in a handful of developing countries where population is
slowing, the cause isn’t something to (2) , because more
people are dying. This trend is called "population fatigue", and it’s beginning in many of the developing countries that have experienced (3) birthrates and sharp population growth for several decades. Governments in these countries are now having trouble dealing with feeding, housing and educating an increasing number of children, (4) at the same time confronting the falling water (5) , deforestation and soil erosion that rapid popu A. e.g. B. i.e. C. etc. D. et al. [判断题] 压缩气体钢瓶或者油桶库房着火，必须在充分冷却，确认无爆炸危险后，方能深入内部设置水枪阵地。（）
A.正确 B.错误 [单项选择]根据英国的票据法，如汇票上载明“付给持票人”，而未载明受款人的姓名，则该记载是（）。
A. 来人式抬头 B. 指示式抬头 C. 限制性抬头 D. 无记名抬头 [单项选择]关于性接触和艾滋病感染关系的描述错误的是（）
A. 同性或异性性接触均具有传染性 B. 同时患其他STD，可增加传染概率 C. 处于血清阳性期的患者传染性大 D. 肛交主动方受感染的几率大于被动方 [单项选择]以下关于CRTSⅠ型板式无砟轨道灌注袋安装不正确的是（）。
A. 灌注袋铺设应平整无褶皱 B. 灌注袋安装时应区分袋的上、下面 C. 灌注袋的灌注口应置于轨道较低侧 D. 灌注袋的U型边切线应与轨道板边缘平齐 [判断题]民航安保事件信息的报送、统计、分析和发布等工作不实行信息共享的原则。 ( )
A.正确 B.错误 [单选题]高压开关柜靠墙布置时，侧面离墙不应小于200mm，背面离墙不应小于( )。
A.450mm B.480mm C.500mm D.1000mm [判断题]轨旁ATP/ATO设备采用“三取二”平台技术
A.正确 B.错误 [判断题]持《全国铁路通用乘车证》可乘坐除国际列车、联运车厢以外普速列车所有座席、卧铺以及动车组列车二等座。
A.正确 B.错误 [多选题]端子排的安装，（ ）是符合规定的。（GB 50171—2012《电气装置安装工程 盘、柜及二次回路接线施工及验收规范》5.0.2）
A.交、直流端子应分段布置 B.潮湿环境宜采用防潮端子 C.端子应无损坏，固定应牢固，绝缘应良好 D.回路电压超过220V的端子板应有足够的绝缘，并应涂以红色标识 [单项选择]下列属于税务机关作出的征税行为的是（）。
A. 加收滞纳金 B. 停止出口退税权 C. 开具外出经营活动税收证明 D. 税收保全措施 [单项选择]根据《中华人民共和国传染病防治法》，发现甲类传染病后（）
A. 城镇在4小时内上报，农村在8小时内上报 B. 城镇在6小时内上报，农村在12小时内上报 C. 城镇在8小时内上报，农村在16小时内上报 D. 城镇在10小时内上报，农村在20小时内上报 E. 城镇在12小时内上报，农村在24小时内上报 [多选题]使用寿命大于或者等于3000发弹的手枪枪种为（ ）。(1.0分)
A.QSZ92式9毫米手枪 B.54式7.62毫米手枪 C.64式7.62毫米手枪 D.77式7.62毫米手枪 [多选题]关于会议排位，领导人数为单数时按单主位排法，是指（ ）。
A.排名第一位的领导居中 B.排名第二位的领导安排在第一位领导右侧 C.排名第二位的领导安排在第一位领导左侧 D.排名第三位的领导安排在第一位领导右侧 [单选题]足月儿，胎头吸引分娩，有窒息史，转入儿科后一直嗜睡、呕吐，枕部有血肿，前囟3cm×3cm，颅缝略宽
首选何种检查确诊（）
A.血培养 B.头颅CT C.血糖 D.血电解质 E.脑脊液 [单选题]在停电的设备或母线上作业前，应经检验确（ ）后方可装设接地线，装好接地线后方可进行作业。
A.无电压 B.无电流 C.无电容 D.工作内容 我来回答: 提交
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