The exhibition is well worth _____ and you can see fancy vases of different dynasties on show there.

u swim in a river or lake, be sure to investigate is below the water surface. Often there are rocks or branched hidden in the water.

tronaut did many experiments in the spaceship, ______much help for knowing space

We advocate the disagreements between China and America_____ through dialogue.[ ]

．— Where did he leave his car key? — It was in the lab he made the experiment.