钯碳催化剂的用量一般为()
A.1%
B.2%
C.5%
D.10%
参考答案:D
_____ is shown in the report, teenager problems are often connected with family lifeeducation.
A.Which
B.As
C.It
D.What
下面不是EDI三要素的是( )。
A.软件B.硬件C.通信网络以及数据标准化D.电子技术