152. When the technique known as gene-splicing was invented in the early 1970’s, it was feared that scientists might inadvertently create an “Andromeda strain,” a microbe never before seen on Earth that might escape from the laboratory and it would kill vast numbers of humans who would have no natural defenses against it.(A) it would kill vast numbers of humans who would have no natural defenses against it(B) it might kill vast numbers of humans with no natural defenses against it(C) kill vast numbers of humans who would have no natural defenses against it(D) kill vast numbers of humans who have no natural defenses against them(E) kill vast numbers of humans with no natural defenses against them我想這句句意應該有假設的口氣，"殺死絕大多數可能沒有防禦能力的人"，但話說回來，用had，表示只有過去(1970)年以前是如此?現在就不會這樣了嗎?
