Again, a very nice summary. Thanks! My opinions:

Discussions:

1. "the Middle Ages" is definitely better.

2. 第一，二句应用被动语气，但不太好，不喜欢这种用法。

Two unequal stones were dropped to the ground at the same time.
Two unequal stones were dropped on the ground at the same time.

Both #3 and #4 are acceptable.

 

 

 

 

Both #3 and

 

所有跟帖： 

• Thank you, Dr. NewVoice. -EnLearner- ♀ (351 bytes) () 08/20/2011 postreply 07:15:58

• Oops, I only looked at grammar, -NewVoice- ♀ (684 bytes) () 08/20/2011 postreply 09:45:46

• just learned: release -> let fall, haha -jennea- ♀ (727 bytes) () 08/20/2011 postreply 09:57:45

• Thanks! Jennea, you are so thorough! Learned. -NewVoice- ♀ (0 bytes) () 08/20/2011 postreply 10:24:47

• 我啥都google，成习惯了～ -jennea- ♀ (0 bytes) () 08/20/2011 postreply 10:50:53

• 关于被动语态 -全国牙防组- ♂ (133 bytes) () 08/20/2011 postreply 08:51:01

• 借地谢谢牙医。你的t和tr的读法说得很好，我一下解决了以前t结尾辅音发不好的问题。 -beautifulwind- ♀ (126 bytes) () 08/20/2011 postreply 08:58:37

• 你那个choi知道怎么回事了没有啊？ -jennea- ♀ (0 bytes) () 08/20/2011 postreply 09:16:43

• 谢谢jennea！choi经过泡泡和你的提示，我的发音得到了native speaker的肯定。 -beautifulwind- ♀ (116 bytes) () 08/20/2011 postreply 09:24:20

• 不用谢。就是因为我自己也不肯定，所以才想知道你的答案～～ -jennea- ♀ (0 bytes) () 08/20/2011 postreply 09:29:54

• 不用谢 -全国牙防组- ♂ (67 bytes) () 08/20/2011 postreply 09:28:15

• 愚教授一直是很大方的。 -beautifulwind- ♀ (0 bytes) () 08/20/2011 postreply 09:32:58

• I did not know this trend. Learned! Thanks! -NewVoice- ♀ (0 bytes) () 08/20/2011 postreply 09:47:38