参考答案：

1）There are several things which are interesting here.

Several things are interesting here.

2）It is encouraging and inspiring to note that sales which are reported right now have increased this month.

Sales have increased this month; the figures are encouraging.(特别说明一下，这句句子是商务英语写作的范畴，一般不用形式主语，不用从句，所以这里不要用it is + aj.句型。)

3）Another factor that adds to the persuasive power of this speech is the vivid example is gives.

The vivid example also makes the speech mor persuasive.