亚硝酸盐中毒是由于妨碍了( )。
A. 血红蛋白携氧
B. 组织细胞呼吸
C. 肺泡换气
D. 泌尿系统排尿
Vocabulary & StructureDirections: In this section, there are 10 incomplete statements. You are required to complete each one by deciding on the most appropriate word or words from the 4 choices marked A, B, C and D.When I am awaybusiness, I contact my office every day by email.
A. with
B. of
C. on
D. to
The decision about such a big project can not be madeeach memeber of the board agrees.
A. if
B. unless
C. though
D. as
No sooner than I realised I'd left the document at home.
A. have we sat down
B. had we sat down
C. we had sat down
D. we sat down