Skyscraper: high building.

En route: on the way to some places.

Sensibly: clearly obviously.

Smuggling: take sth out of your country illegally.

Emigrate: to leave your own country and live permanently in another country.

There are many skyscrapers of downtown HK, just like other modern cities. But why lots of people sensibly want emigrate into HK? Because the advantage of social welfare, however, some people smuggling en route between HK and mainland.