Faced with a bill for $10,000, _____.

A．Smith has taken an extra job

B．the boss has given Smith an extra job

C．an extra job has been taken

D．an extra job has been given to Smith

骨折愈合的第三期是（）。

A．原始骨痂形成期

B．血肿机化演进期

C．骨痂改造塑形期

D．膜内化骨期

E．软骨内化骨期