【单选题】平面任意力系有 ( ) 个独立的平衡方程,平面平行力系有 ( ) 个独立的平衡方程。
【单选题】—Do you know _____ for Shanghai last night? —At 9:00. [ ]
B.
what time does he leave
D.
what time did he leave
【单选题】“你选书,我买单”的活动可以在什么时间参加?
D.
图书馆每年4月读书月和10月咨询服务月活动期间
【单选题】What time does the woman ask the man to come to the office?
C.
At 10:00 on Wednesday.
【判断题】《论语·八佾》中“郁郁乎文哉”指的是西周的礼乐。()
【简答题】平面任意力系有____个独立的平衡方程,平面汇交力系有____个独立的平衡方程,平面平行力系有____个独立的平衡方程,平面力偶系有____个独立的平衡方程。
【单选题】What is Cas9 and what does it do?
A.
an RNA molecule that binds to target DNA via complementary base pairing
B.
a DNA sequence that binds the Cas9 protein
C.
a viral protein that disrupts bacterial membranes
D.
a protein enzyme that cuts both strands of DNA at sites specified by an RNA guide