Expose: to put somebody/something in a place or situation where they are not protected from something harmful or unpleasant 使面临,使遭受(危险或不快)
to expose yourself to criticism/ridicule 使自己受到批评/嘲笑
Do not expose babies to strong sunlight. 不要让婴孩受到强烈的阳光照射.
Extend: to make a business, an idea, an influence, etc. cover more areas or operate in more places 扩大...的范围(或影响)
The company plans to extend its operations into Europe. 公司打算将业务扩展到欧洲.
The school is extending the range of subjects taught. 学校正在拓宽授课学科的范围.