請教一道文法題!

deepocean101

The population of California more than doubled during the period 1940-1960, creating problems in road-building and provide water for its arid southern section.

請問一下，這道題明顯的是要將provide 改為proivding

但是The population of California more than doubled during the period 1940-1960

這句的動詞在哪呢?是否該在more 前加上 is呢?

enjoylife517

double 本身就是动词，所以这里不要用is，而且也没有被动的情况。double就是这么用的

有has doubled 的用法。呵呵

deepocean101

謝謝!!!!!!!!