题目内容
18．Human population growth will be probably the most serious problem if itisn't controlled （not control） properly．分析 人口的增长如果不适当的控制，就可能是最严重的问题．
解答 答案：isn't controlled．if引导的条件状语从句，遵循主将从现的规则，故从句用一般现在时，结合not control用否定式，主语it替代Human population 是动词control"控制"的承受者，构成被动关系，故用一般现在时的被动语态am/is/are+过去分词，主语it三单，故is，加上not缩写成isn't，control的过去分词是controlled，故答案是isn't controlled．
点评 一般现在时的被动语态am/is/are+过去分词的呈现，各种类型的被动语态的构成要理解掌握．
练习册系列答案
相关题目
9．Sorry，the bus is too __________，we can't take any more passengers to the park．（ ）
| A． | creative | B． | courious | C． | crowded | D． | classical |
9．September is the time for students to go back to school!For Chinese students，most schools start on the same day．We will share summer stories with the same classmates （61）Bthe first-year students．But in US schools，students get ready for classes a little（62）C．
First of all，US schools don't all start on the same day．Classes begin any time between August and September．Every（63）Adecides when to begin their classes．If summers are too（64）C then school will usually start a little later．
Every year we usually see the same teachers and classmates，but US students have some big changes．In US high schools，teachers divide（65）B into different levels or focuses．Students can choose their favorite teachers and courses according to their abilities and（66）B．This means that every year students will（67）Bdifferent classrooms for each class．They will meet（68）A classmates and teachers in each one．Also，students will go to school a few days early to get their（69）Cso that they can know the classes every day．
For first year students，the first day of school also means they finally get their own lockers（储物箱）．Primary school students in the US have to share closets（储物柜） with their（70）A．But once students make it to junior high they finally get one．
First of all，US schools don't all start on the same day．Classes begin any time between August and September．Every（63）Adecides when to begin their classes．If summers are too（64）C then school will usually start a little later．
Every year we usually see the same teachers and classmates，but US students have some big changes．In US high schools，teachers divide（65）B into different levels or focuses．Students can choose their favorite teachers and courses according to their abilities and（66）B．This means that every year students will（67）Bdifferent classrooms for each class．They will meet（68）A classmates and teachers in each one．Also，students will go to school a few days early to get their（69）Cso that they can know the classes every day．
For first year students，the first day of school also means they finally get their own lockers（储物箱）．Primary school students in the US have to share closets（储物柜） with their（70）A．But once students make it to junior high they finally get one．
| 61．A．including | B．except | C．besides |
| 62．A．early | B．late | C．differently |
| 63．A．school | B．city | C．town |
| 64．A．dry | B．cool | C．hot |
| 65．A．students | B．classes | C．subjects |
| 66．A．ages | B．interests | C．habits |
| 67．A．see | B．enter | C．build |
| 68．A．new | B．special | C．unfriendly |
| 69．A．homework | B．books | C．schedule |
| 70．A．classmates | B．teachers | C．owners． |
13．-I'm falling to pieces．Everything is turning against me．
-____________!I believe you can deal with it．（ ）
-____________!I believe you can deal with it．（ ）
| A． | Cheer up | B． | Be careful | C． | Calm down | D． | Look out |
7．Ge Yunlin was _______ of all the contestants（选手） in Super Brain．（ ）
| A． | Younger | B． | the younger | C． | youngest | D． | the youngest |