干线

hé liú de gàn xiàn

河流的干线

mainstream

méi qì guǎn gàn xiàn

煤气管干线

gas main

jiāo tōng gàn xiàn

交通干线

main lines of communication

gōng diàn gàn xiàn

供电干线

supply mains

tiě lù gàn xiàn yǐ jīng diàn qì huà le

铁路干线已经电气化了。

The main line has been electrified.

gōng lù gàn xiàn zāo shuǐ yān mò wǒ men zhǐ néng zé xiāng jiān xiǎo jìng rào xíng

公路干线遭水淹没，我们只能择乡间小径绕行。

The main road was flooded so we had to go round by narrow country lanes.