测得某食物含氮量为5.502%，其粗蛋白含量为（）
A.14.4%
B.18.2%
C.20.5%
D.30.1%
E.34.4%
参考答案：E
We have to ________ our school trip till next week because of the heavy rain. [ ]
A. put off
B. put on
C. put up
D. put down
填空
1. His family _____ （be）very big. There are six people.
2. My family _____ (be) very well.
