I'm afraid she's not here at the moment. A: then B: now C: later D: soon

中国大学MOOC: The flight is ______. I think I’m going to volunteer to take a later flight.

大肠杆菌长为（） A: 0.1～1μm B: 1～4μm C: 4～10μm D: 10～40μm E: 40～100μm

青书学堂: (4).  The bus driver drove the writer home later because ________.

I’m very busy ___ present. Can I call you back later? A: with B: in C: about D: at

质量摩尔浓度为m的Na3PO4溶液，平均活度系数为γ±，则电解质的活度为：（） A: a（B）=4（m/mθ）4（γ±）4 B: a（B）=4（m/mθ）（γ±）4 C: a（B）=27（m/mθ）4（γ±）4 D: a（B）=27（m/mθ）（γ±）4

I'm a bit tied-up at the moment. I ______ be able to see you later but I'm not sure yet. A: must B: can't C: have to D: might

用动态规划策略求解矩阵连乘问题1 2 3 4 M*M*M*M，其中1M（20*5）、2M（5*35）、3M（35*4）和4M（4*25），则最优的计算次序为（）。 A: 1 2 3 4 ((M*M)*M)*M B: 1 2 3 4 (M*M)*(M *M ) C: 1 2 3 4 (M*(M *M))*M D: 1 2 3 4 M*(M *(M *M ))

I'm busy right now. Can you _______ later? A: hang up B: call back C: call through

Those who take risks they regret later value short-term gain most.  A: A B: B C: C D: D E: E F: F G: G H: H I: I J: J K: K L: L M: M N: N