A:holding
B:to hold
C:held
D:hold
A. doctor B. nurse C. teacher D. farmer E. singer F. writer
⑴ ____ ⑵ ____
⑶ ____ ⑷ ____
⑸ ____ ⑹ ____
Amy has got lots of friends.(改为一般疑问句并做否定回答)
____Amy ____lots of friends? No, ____ ____.
人体呼出的二氧化碳产生于( )
已知:①气态链烃A在标准状况下的密度为1.875g·L-1;