我没怎么旅游过，但是，在我离开美国前，去过大峡谷和三藩市。

I have not traveled much yet; however, I (visit) the Grand Canyon and San Francisco by the time I leave the United States.

youdao

但是，位于美国加州奥洛维尔市巴特学院的学生走得更远，他们建造了巨大的太阳能电池阵列，靠着中央大峡谷的充沛阳光自给自足。

But the students at Butte College in Oroville, California, will go a lot further, thanks to the Central Valley sunshine.

youdao

但是，位于美国加州奥洛维尔市巴特学院的学生走得更远，他们建造了巨大的太阳能电池阵列，靠着中央大峡谷的充沛阳光自给自足。

But the students at Butte College in Oroville, California, will go a lot further, thanks to the Central Valley sunshine.

youdao