The earth could be younger and took more than three times longer to form than _______ thought, according to a new study.

A．favorably

B．deliberately

C．practically

D．previously

英国开展工业革命的主要动力是

A．积累了丰厚的资本

B．市场需求不断扩大

C．雇佣劳动力充足

D．生产技术持续进步