【单选题】下列有关群落初生演替和次生演替的叙述中,错误的是
D.
两种演替总会使群落中物种丰富度增大、结构更复杂
【单选题】There is a police car in front of the house of our neighbour's. _____ do you think _____ ?
C.
What;of being happened
【简答题】在公式s=vt+5t 2 中,已知s、t(t>0),那么v=______(用s、t的代数式表示).
【判断题】在温度的换算公式中,tK=273+t℃(K)。
【判断题】在温度的换算公式中,t℃= tK- 273(℃)。
【简答题】在公式s=50t中常量是______,变量是______.
【单选题】There has been no _____ so far from the police about the cause of the poor girl's death after the college entrance examination. [ ]
【单选题】She's a police officer, so she has to wear a ________ at work.
【简答题】在公式v=av 0 +2t中,已知v=100,v 0 =20,t=4,则a=______.