【单选题】The two essential parts of a deal negotiation are ( ) .
A.
Enquiry and acceptance
B.
Offer and counter-offer
C.
Counter-offer and acceptance
【判断题】山水画创作的源泉来源于生活,来源于大自然,古今画家都重视写生,许多作品都是在写生的基础上创作的。
【单选题】________are two essential factors to form a contract.
B.
Offer and counter-offer
C.
Enquiry and acceptance
【简答题】外周免疫器官包括____________、____________和黏膜相关淋巴组织。
【多选题】What are the two essential components of scientific research?