棉花白，谷子黄，红脸关公是高粱。冬瓜矮，南瓜胖，丝瓜上架细又长。
已知a+b=16，b+c=12，c+a=10，则a+b+c等于（ ）
给加下划线字选择正确的解释。
欲穷千里目（ ）
It's 11: 00 pm now, but the light in Peter's room is still on. He must have forgotten _______ before going to bed.
