两步试验的英文

• two stetest twostage testt

• 两:    two
• 步:    pace; step
• 试验:    experiment; test; trial
• 初步试验:    early test; exploratory test; pilot test; pilottest; preliminary experiment; preliminary testing; preliminary trial; primary test; rough test; trial test
• 初步试验；筛选:    screening test