题目

Computers and the advantage _________ gave us _________ being made better use of presently. A.that;is       B.they;are C.it;was       D.which;were  答案：B 解析: 定语从句及主谓一致的运用。they代表computers,后者presently的出现表明是现在被更好的利用,且主语为复数。如图所示，请从图示情景中找出一个物理现象，并说明所对应的物理知识．示例物理现象：________物理知识：________．