引导宾语从句的that可省略吗

　　一般的,that引导名词性从句时,只起连接从句的作用,本身没有任何意义,因此在从句中不充当任何句子成分.
　　在GMAT语法中,认为在引导宾语从句时,唯一做的就是降级、连接,如果去掉功能体现不出来,所以坚决不能省.但在引导定语从句时充当定从中的宾语时可以省,因为它那时是关系代词,可以从从句中缺一个成分看出来降级.
　　在GMAT语法严格遵守连词数=谓语动词数-1.比如造个句子：He believed that each individual is responsible for the environmental protection of the earth.谓语动词有believe 和is两个,一个主句的,一个从句的,2-1=1,所以这个连词that不能省.
　　所以严格来说,引导宾语从句的that是不可以省略的,所以如果以后想考GMAT的话,要记住这个规则哦.中国的语法专家建议综合考虑,决定保留老外口语中的that可省这一点,但在有一些比如agree,argue,hold,learn,observe,remark,suggest,indicate,conceive这种比较正式的书面语的谓语动词后,就规定that不可省略;而像hear,know,grant,say,see,perceive,confess,consider,declare,understand,propose这些词呢,口语书面都可以,that就可省可不省;但如果是think,suppose,believe,presume,dare say这种口语词时,that通常要省略.
　　that不可省略的情况：
　　1.在主语从句、表语从句、同位语从句中(除宾语从句),that 不能省.
　　That the seas are being overfished has been known for years.(主语从句)
　　The truth is that nobody knows who invented eyeglasses.(表语从句)
　　We have to face the fact that land is fragile.(同位语从句)
　　2.在it作形式宾语的宾语从句前,that不可省.
　　They found it difficult that they would finish their work in two days.
　　3.在由and或or所连接的两个宾语从句时,第一个从句中的that可以省;而第二个从句中的that不能省.
　　It is depressing to think (that) life is purposeless and that evolution has no higher destination.