. The latest job report gave a mixed picture of employment in the US, leaving investors without any clear sign ________ the economy is improving.
| A．which | B．that | C．what | D．if |
It was with great joy the couple found their missing son after 18 years.
| A．when | B．that | C．what | D．which |
What ______ the doctors most was that they could not find the cause of the disease.
| A．astonished | B．puzzled | C．surprised | D．amused |
_____ their hats into the air, the fans of the winning team let out loud shouts of victory.
| A． To throw | B．Thrown | C．Throwing | D．Being thrown |
On the annual International Volunteers Day, the world _____ the work of millions of people who give their time to help others.
| A．abolishes | B．accompanies | C．acknowledges | D．appeals |
It was____to watch small childen play games.
| A．pleased | B．pleasure | C．glad | D．fun |