There is／are_________consonant cluster(s)in the word“infrastructure”．

[单选题]Which of the following consonant clusters may not serve as the beginning of

[名词解释] cluster sampling

[名词解释] Cluster簇

[名词解释] CD(cluster of differentiation)

[名词解释] 协和音程与不协和音程（Consonant，Dissonance）

[名词解释] 丛集性头痛（cluster headache）

[单选题]Consonant articulation is relatively easy to feel and as a result is most c

[单选题]Consonant articulation is relatively easy to feel and as a result is most c

[单选题]The [authorities]approved the new round of local infrastructure development

[单选题]IT设施库（IT Infrastructure Library，ITIL）是由哪个国家开发的（）A . 美国B . 德国C . 澳大利亚D . 英国