Question

_________, I think, and the problems would be settled.

A．If you double your efforts	B．Making more efforts
C．So long as you don’t lose heart	D．A bit more effort

Answer 1

D

根据句中的连词and可知此空缺少祈使句，如果没有and则A、C两个选项都正确。句意：我认为努力些问题就会解决。