二氧化碳在血液中的主要运输形式是:( )
A. 物理溶解
B. 碳酸氢盐的形式
C. 氨基甲酸血红蛋白形式
D. 以上都不是
The bad weather had driven tourists ( ).
A. of
B. away
C. in
D. up
The company has( )a new toy and it sells well in the market.
A. worked
B. taken
C. opened
D. designed
The plane was about to take ( ), and yet I left my ticket behind.
A. off
B. to
C. on
D. for