【简答题】回答下列问题: (1)杂交育种是通过品种间杂交创造新类型的育种方法。其特点是将两个纯合亲本的________通过杂交重组在一起,再经过选择和培育获得新品种。 (2)若两个纯合亲本杂交,F 1 自交能产生多种非亲本类型,其主要原因是F 1 在形成配子时,位于________基因自由组合,或者位于________基因通过非姐妹染色单体交换进行重新组合。 (3)假设杂交涉及到n对相对性状,每对相对性状各...
【简答题】No sooner ______ (we arrive) at our house than it started to rain.
【单选题】We mush our house once a week.
【判断题】在旅游团抵达B市时,如有行李托运,全程导游应将旅游团行李托运单交给B市行李员。( )
【单选题】As to the question of whether we will sell our house or who we shall sell the house to, you ________ have an answer by tomorrow. [ ]
【判断题】无失真传输系统的幅度频率响应特性是常数。
【判断题】在旅游团抵达B 市时,如有行李托运,全程导游应将旅游团行李托运单交给行李员。( )
【单选题】As to the question of whether we will sell our house or who we shall sell the house to, you ____ have answer by tomorrow.
【简答题】The tenant mush be prepared to decorate the house ________ the terms of the contract. A) in the vicinity of B) in quest of C) in accordance with D) in collaboration with
【判断题】系统无失真传输要求系统频率响应的幅度特性是一常数,相位特性是一过原点的直线。()