Whenever we hear of a natural disaster, we feel sympathetic to the people to be affected.（）

单项选择题It was now clear that no such weapons were manufactured and none been found.（）

A．was found
B．were founded
C．has been found
D．have been founded

单项选择题He had studied hard, he would have been able to pass the exam.（）

A．He had studied harder
B．If only he studied more
C．Had he studied harder
D．When he studied more