1. It was not until 1936___baseball became a regular part of Olympic Games.

　　A. then B. which C. that D. when

　　2. ___in 1943___the harmful smog made its appearance in Los Angeles.

　　A. Only… that B. It was… then

　　C. That it was… when D. It was… that

　　3. It was on the National Day___ she met with her separated sister.

　　A. that B. where C. when D. which

　　4. ___the 1500's___the first European explored the coast of California.

　　A. It was until……then

　　B. It was not until … when

　　C. It is until……that

　　D. It was not until……that

　　5. ___in this room that our first meeting was held.

　　A. Just when B. When C. Where D. It was