下列物质中,不是由DNA分子的遗传信息直接控制合成的是 [ ]

A．胃蛋白酶

B．尿激酶

C．雌性激素

D．卵清蛋白

Those who are not admitted to university, ________, may attend some other courses or classes for adult higher education.

A．though important

B．if possible

C．unless necessary

D．if ever