题目内容
9．I don't know if he _______ tomorrow．If he ______，I'll tell him about it．（ ）| A． | will come，will come | B． | comes，comes | ||
| C． | comes，will come | D． | will come，comes |
分析 我不知道他明天是否回来．如果他来的话，我将告诉你．
解答 答案：D．对于第一个句子，根据本句放在I don't know 之后，可知本句考查了宾语从句的用法．在宾语从句中，如果主句是一般现在时，从句的时态根据自身的时间状语确定，所以，本句的时态应根据tomorrow可知，应用一般将来时．对于第二个句子，根据句型结构可知，本句是if引导的条件状语从句，其用法是"主将从现"，即主句用将来时，从句用一般现在时．故选D．
点评 点评：本题实际是考查if的用法，以if引导的从句有两个，一个是宾语从句，一个是条件状语从句．做题时应该首先明确它引导的是什么从句，然后根据它的时态用法，来确定选项．
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18．I would like to talk to you about space vegetables，and to show you that space vegetables are healthy and good for you．
Space vegetables are grown from seeds（种子） that have been taken to and brought back from outer space．The seeds are affected by radiation and low gravity in outer space．When they are brought back to the Earth，these seeds produce vegetables that are bigger，healthier and more nutritious （有营养的）than normal vegetables．However，some people worry about eating space vegetables．They think that space vegetables might not be good for us and could give us cancer as a result of their exposure （暴露）to radiation in space．People should not be scared，as space vegetables are actually perfectly healthy．
Here are some facts that you should know about space vegetables：
Space vegetables are grown from seeds that are carefully selected．When seeds are brought back from space，people test the seeds to make sure that the vegetables they grow will be safe to eat．There are no traces of radiation after testing．
Space vegetables are better for you than normal vegetables．For example，space tomatoes stay fresh for twenty days，which is one week longer than normal tomatoes．Another popular space vegetable is the pepper（辣椒）．Space peppers contain 20per cent more Vitamin C than normal peppers．
After genetically modified（改进的） foods come onto the market，people worry that they are eating unknown things．For example，if nut genes are put inside potatoes，people allergic（对…过敏） to nuts might get very sick from eating these potatoes because they do not know they are also eating nuts．Unlike genetically modified foods，space vegetables have not been genetically changed．This means that no new genes are put into the vegetables．Therefore，they won't damage your health．
Space vegetables are grown from seeds（种子） that have been taken to and brought back from outer space．The seeds are affected by radiation and low gravity in outer space．When they are brought back to the Earth，these seeds produce vegetables that are bigger，healthier and more nutritious （有营养的）than normal vegetables．However，some people worry about eating space vegetables．They think that space vegetables might not be good for us and could give us cancer as a result of their exposure （暴露）to radiation in space．People should not be scared，as space vegetables are actually perfectly healthy．
Here are some facts that you should know about space vegetables：
Space vegetables are grown from seeds that are carefully selected．When seeds are brought back from space，people test the seeds to make sure that the vegetables they grow will be safe to eat．There are no traces of radiation after testing．
Space vegetables are better for you than normal vegetables．For example，space tomatoes stay fresh for twenty days，which is one week longer than normal tomatoes．Another popular space vegetable is the pepper（辣椒）．Space peppers contain 20per cent more Vitamin C than normal peppers．
After genetically modified（改进的） foods come onto the market，people worry that they are eating unknown things．For example，if nut genes are put inside potatoes，people allergic（对…过敏） to nuts might get very sick from eating these potatoes because they do not know they are also eating nuts．Unlike genetically modified foods，space vegetables have not been genetically changed．This means that no new genes are put into the vegetables．Therefore，they won't damage your health．
| Space vegetables | |
| Space vegetables are healthy，good and safe for you to eat． | |
（1）Steps taken to ensure the quality of space vegetables | Before being taken to the outer space，the seeds are carefully selected． |
| When being brought back from space，seeds are （2）tested to see whether there are traces of radiation which might （3）lead to cancer．The testing has proved that they are perfectly healthy． | |
（4）Advantages of space vegetables | After being affected by the radiation and low gravity in outer space，the seeds produce bigger and healthier vegetables．For example，space peppers contain more Vitamin C． |
| Space tomatoes stay much longer than normal tomatoes． | |
| There is no （5）harm of eating something that may damage your health because none of the genes is changed． | |