专升本考试

【单选题】 It is essential that mankind ______ ways and means to protect the environment.
A．adopt
B．have adopted
C．will adopt
D．will have adopted

网考网参考答案：A
网考网解析：
it is essential that句型使用虚拟语气，从句中谓语动词用should+动词原形，或直接用动词原形。 查看试题解析出处>>