【单选题】听力原文:W: I just made a jar of jam this morning, and now I can' t find it anywhere. Do you know what happened to it? M: Did you hear a crash? That was it. I' m just as clumsy as ever. Q: What is the pro...
A.
The woman doesn't like jam.
B.
The woman forgot where she had left the jar.
C.
The man had art accident.
D.
The man broke the jar.
【判断题】在生物界中,N-乙酰胞壁酸、磷壁酸、D型氨基酸和m-二氨基庚二酸几种成分是细菌细胞壁所特有的。( )
【单选题】现用质量分数为98%的浓硫酸(密度是1.84 g/cm3)配制560 g质量分数为14%的稀硫酸,下列有关叙述中正确的是
B.
配制稀硫酸时,一定不能用天平称量所需浓硫酸的质量
C.
将480 mL水倾倒入盛有80 mL 98%的浓硫酸的500 mL量筒中
D.
将80 g 98%的浓硫酸沿1000 mL烧杯内壁缓缓倒入480 mL水中,并不断搅拌
【单选题】第一节 听下面5段对话。每段对话后有一道小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。 听力原文:M: Where did you say you put them? W:I didn't say, but keep looking till you find them. Where d...
C.
She couldn' t remember exactly.
【单选题】现用质量分数为98%的浓硫酸(密度是1.84gcm ﹣3 )配制560g质量分数为14%的稀硫酸时,下列有关叙述正确的是 [ ]
B.
配制稀硫酸时,一定不能用天平称量所需浓硫酸的质量
C.
将80 mL98%的浓硫酸与480 mL水混合
D.
将80g 98%的浓硫酸与480 mL水混合