图像: image, picture, graphic...
密集: concentrated, crowded together, intensive, compressed...
批: to ascertain, to act on, to criticize, to pass on, classifier for batches, lots, military flights, tier (for the ranking of universities and colleges)...
游行: march, parade, demonstration...
用得着: to be able to use, useable, to have a use for sth, (in interrogative sentence) to be necessary to...
安全: safe, secure, safety, security...
为何: why...
发电: to generate electricity, to send a telegram...
阔: rich, wide, broad...
