Citizens in a democratic country (has, have) to select a leader through election process.

• has

• have

• will

• can

Pump prices (go, goes) up rapidly depending on the scarcity of supply.

Terrorists groups (behead, beheaded) foreign journalist 7 years ago.

Transport group (express, expresses) fare hike if oil prices (will continue, continues) to rise next week.

Overseas workers (is expected, are expected) to go back home in the coming years.

Today's youth (know, knows) the difference between real frienships from mere acquaintances.

Typhoon Hagupit (was, were) the most destructive typhoon last month.

Merchandises from China (will continue, continue) to flock the global market.

Persona non-grata (is, are) declared whenever a person/an individual utters or behaves inappropriatey in a particular place or country.

Global warming (become, becomes) an alarming problem worldwide.