旅游企业为了更好地占领市场和开拓市场，同时也为了避免单一经营的风险，应该采取()发展战略。

A．差异性

B．差异扩张

C．多样化

D．一体化

They _______ Tom to record the hit single.

A．kept up with

B．caught up with

C．put up with

D．teamed up with