A woman passes by a sign of the World Economic Forum (WEF) in Davos, Switzerland, Jan. 21, 2019. The WEF Annual Meeting will kick off in Davos on Tuesday. (Photos: Xinhua)

A security personel stands guard on the roof of Davos Congress Center, which will host the upcoming 49th Annual Meeting of the World Economic Forum (WEF), in Davos, Switzerland, Jan. 21, 2019. The WEF Annual Meeting will kick off in Davos on Tuesday.

Photo taken on Jan. 21, 2019 shows the logo of the World Economic Forum (WEF) in Davos, Switzerland. The WEF Annual Meeting will kick off in Davos on Tuesday.

Photo taken on Jan. 21, 2019 shows the logo of the World Economic Forum (WEF) in Davos, Switzerland. The WEF Annual Meeting will kick off in Davos on Tuesday.

Security personel patrol near Davos Congress Center, which will host the upcoming 49th Annual Meeting of the World Economic Forum (WEF), in Davos, Switzerland, Jan. 21, 2019. The WEF Annual Meeting will kick off in Davos on Tuesday.

Photo taken on Jan. 21, 2019 shows the logo of the World Economic Forum (WEF) in Davos, Switzerland. The WEF Annual Meeting will kick off in Davos on Tuesday.

Workers prepare for the upcoming 49th Annual Meeting of the World Economic Forum (WEF) in Davos, Switzerland, Jan. 21, 2019. The WEF Annual Meeting will kick off in Davos on Tuesday.