是的,what在此句中作主语成分.Mr Smith is searching the internent to find that what is the cause of the earthquake in Qinghai这句话对吗有问题：第一，Internet没有大写；第二，不应该是find，而应该为find out，“找出，查明”；第三，find后面为宾语从句，应该用陈述语序，即主语在前，谓语在后。what the cause of the earthquake in Qinghai is。