1.be happy that 中that 引导的是原因状语从句,说明高兴的原因,相当于because 引导的句子.“be+形容词+that从句”是英语的表达方式之一,例如:I am very happy that you could visit us."您能来拜访我们,我们很高兴".再例如:He was glad that he had made great progress in his study."他很高兴自己在学习中取得了很大的进步".表语从句是紧跟在连系动词(即系动词)后,例如:The teacher's decision is that we will have a meeting next Wednesday."老师的决定是我们下周星期三开会".
2.instead of complaining that the rosebush is full of thorns,be happy that the thorn bush has roses.
“不要抱怨玫瑰丛(或者:蔷薇丛)长满了刺,相反,为刺丛有玫瑰(或者:蔷薇)而高兴吧”."be happy that ..." 是祈使句,用动词原形,所以用be原形.
再问： 怎么有人说be happy that是宾语从句 这个that不做成分吧？ 表语从句的that也不做成分吧？
再答： 回答您的问题如下： 1. 判断that 从句是状语从句还是宾语从句还与整个句子的意思相关。例如您的例子中：be happy that the thorn bush has roses. “为刺丛有玫瑰(或者: 蔷薇)而高兴吧”，从语义上讲，显然“刺丛有玫瑰(或者: 蔷薇)”是高兴的原因，所以that从句是原因状语。而在 “I am afraid that he will not come this afternoon.” “恐怕他今天下午不会来”这句话中，“I am afraid..." 是"I think..." 的委婉表达方式，相当于“I personally think...” "我个人认为"，所以将“I am afraid that he will not come this afternoon.” 改成 “I personally think that he will not come this afternoon.” 是完全可以的。而在“I personally think that he will not come this afternoon.” 中，that 从句是think 的宾语，所以，在“I am afraid that he will not come this afternoon.” 中，that从句是宾语从句。 所以从句种类的划分与语义有关。 2. 您说得对：be happy that...和表语从句中的that 都不作句子成分。
